I have been eliminated from SCL, so here are my VR changes. My personal VR can be found here. I'm also working on our SCL team dump, where I will go in detail about a lot of these Pokemon, especially the sets we popularized. The VR should definitely be updated soon with SCL ending and there being a ton of nominations. I suppose waiting until DWCoP ends wouldn't be the worst, though.
Rises
Landorus: Tier 3 -> Tier 1
Agree with the other nominations fully. This was the most restrictive Pokemon while building during my SCL experience, and I would definitely include it on any metagame survey the council puts out either when SCL or DWCoP ends. It's extremely powerful, fast, and even has a lot of cool options for its last moveslot -- Psychic is really nice for beating opposing Landorus and also 2HKOs Amoonguss through Sitrus Berry, Focus Blast hits Porygon2, Kyurem-Black, and Celesteela, Substitute creates free turns and punishes the opposition for trying to dance around it, while even Stealth Rock is viable. This was the second most popular Pokemon during the SCL regular season and forced Pokemon such as Celesteela and Zapdos to rise to try to check it. This should be an easy agree.
Celesteela: Tier 4 -> Tier 2
Agree. Meteor Beam Celesteela puts on immense offensive pressure with its dual STABs as well as Meteor Beam to hit would be checks like Zapdos, Volcanion, and Incineroar. Even if the surprise factor is gone, it's really easy to stack Special Attack raises with Meteor Beam and Beast Boost and eventually win the game. It's also one of the few things that switches into Landorus, although it must watch out for Focus Blast, which is extremely important. This is the best Steel-type in the metagame. 12th in overall SCL regular season usage, including an amazing 7/10 uses in Week 7. Also, don't run the Leech Seed set, it sucks.
Mew: Tier 3 -> Tier 2
I agree. Mew's versatility and reliable support prowess is very good. Fake Out, Tailwind, and Stealth Rock have always been great, but stax and Lunar. introduced us to the amazing Snarl + Will-o-Wisp set that can almost win games on its own at some points. It can do even more, including Coaching, Demon Mew, and even offensive sets with Expert Belt and Tailwind. It being one of the most reliable Tailwind setters as well as the new Snarl + Will-o-Wisp set has pushed it to Tier 2. Also sitting at 7th in usage for the SCL regular season.
Naganadel: Tier 3 -> Tier 2
Agree. Z Strats and I spammed this more than anyone, but I really believe it should be Tier 2. Dragon / Poison / Fire coverage is extremely solid, and hits like a truck when running Modest, which even lets it OHKO Metagross with Fire Blast. It's the fastest Tailwind setter bar Whimsicott and offers key resistances to Fire, Water, Grass, and Fighting. It checks a lot of boxes while building and matches up nicely to a lot of common Pokemon (Rillaboom, Landorus, Urshifu-R, Tapu Fini, Rain etc.) and is the premier Tailwind setter for offensive teams, but still works on balance and even Semiroom. I would definitely give this a try if you haven't already.
Zapdos: Tier 3 -> Tier 2
Agree. Another Platoon special, Zapdos is also underutilized. Great Tailwind setter (one of something like 3.5 viable ones), one of the few switch-ins to Landorus, matches up well into Urshifu-R, Rillaboom, Tapu Fini, and more, and hits very hard with Magnet set. It has some nice options for the last move as well, including Whirlwind, Toxic, Volt Switch, and Protect. Synergizes well with Landorus, Urshifu-R, and Nihilego as well. Hurricane is great, just hit. I wouldn't hate it staying in Tier 3, but Tier 2 is better.
Nihilego: Tier 4 -> Tier 3
Nihilego moment. This is a more recent trend, but I think it's definitely a strong one. Its 103 Base Speed is huge, outpacing the likes of Landorus, Urshifu-R, and two of the three most common Tailwind setters. Landorus' rise has seen a big decrease in Zygarde usage, while an increase in Zapdos which is a huge plus. Even Celestela gets 2HKOd by Meteor Beam into Power Gem while never OHKOing back, even at +1. Nihilego also matches up well into Landorus structures, and especially those which feature Zapdos as the Tailwind setter. It's also great into Rillaboom, Tapu Fini, Incineroar, Volcanion, Kyurem-B and more. In case you haven't noticed, I really think Poison is a strong offensive typing, especially when you combine it with something strong like Landorus, Naganadel, and Nihilego do.
Kyurem & Alola NInetales: UR -> Tier 4
Hail is pretty good. Ice is a pretty clickable offensive typing, and the playstyle has tools to play around Diancie / Metagross / Trick Room. We can even see in the SCL Replay that YoBuddy has Celesteela under Trick Room but it doesn't matter because he makes minimal progress due to Aurora Veil.
https://replay.pokemonshowdown.com/smogtours-gen8doublesou-584448
https://replay.pokemonshowdown.com/gen8doublesou-1423306761-iv0gtjbfhbnaga5ldbp47ijm6l6caobpw
Whimsicott: UR -> Tier 4
Prankster Tailwind / Encore / Fake Tiers is really good, especially with great beneficiaries such as Landorus and Naganadel. Great into all other offense besides Psychic Spam. Rillaboom is nowhere near mandatory so switching up your Grass-type is fine. Even after the disastrous start where Tailwind and Fake Tears do nothing, Whimsicott still wins the game with Prankster Encore.
https://replay.pokemonshowdown.com/smogtours-gen8doublesou-590454
https://replay.pokemonshowdown.com/smogtours-gen8doublesou-590466
For the past new nominations, we also have more testing replays against other SCL players, but I'll have to see if I'm allowed to share them. I'm also sure other players tested this during the season and have winning replays.
There are some other things I'd rank that other people used, but I don't feel like collecting replays so if other people want to do them please feel free.
Drops
Rillaboom: Tier 1 -> Tier 2
Do not think this has the splashability it had earlier in the generation, nor is it basically mandatory. Amoonguss and even Tsareena are both great options for Grass-types (Amoonguss especially was hardly viable during OSDT metagame, which also had Kartana which went excellently with Rillaboom), while I don't even think using one is needed at all. Both us and Nails + umbry only ran 3/9 Rillaboom in SCL for example. All its tools are still worthwile, but I wouldn't place it in the same tier as Landorus or Kyurem-B anymore. Rillaboom in Tier 1 would be okay, but Tier 2 is better.
Dragapult: Tier 2 -> Tier 4
Agree. This Pokemon is actually terrible. I have one Dragapult team in my builder that I never actually got around to testing because it had a Dragapult on it. If you want a fast Dragon-type, use Naganadel which also sets Tailwind and hits way harder. Dragapult hates Incineroar, Porygon2, Tapu Fini, and Diancie all being a lot better than they were during OSDT (and Kartana being banned as well as offense being downgraded), as well as most Rillaboom running Knock Off. Choice Specs Shadow Ball doesn't even OHKO Mew which is just embarrassing. This was actually brought eleven times in SCL, but performed poorly with a 36.36% win rate. Besides the game is won on team preview because Frania brought a team from last year's DWCoP, I can't remember it doing anything noticeable.
Genesect: Tier 2 -> Tier 3
Genesect is an unfortunate casualty of Landorus' rise, as the Landorus soft checks in Celesteela and Zapdos also match up well against Genesect. The rest of the OSDT -> SCL metagame shift isn't particularly kind either. This Pokemon was also used eleven times, but performed even worse with an unfathomable win rate of 18.18%, which is the lowest beside 0%. It saw 2 uses in Week 1, 2 in Week 2, 3 in Week 3, 2 in Week 4, and then a whopping 2 the reason of the entire regular season. It was able to do something productive once this season (Mishimono vs. Qwello Lee, Week 2), and it was its only win besides a mirror match.
Heatran: Tier 2 -> Tier 3
Easily the worst of the three main Fire-type Pokemon. Incineroar's support ability is unmatched, Volcanion thrives on Semiroom, which leaves Heatran seeing most of its usage on more offensively-oriented structures. 13 uses compared to Incineroar's 33 and Volcanion's 21.
Zeraora: Tier 2 -> Tier 3
Zeraora is often too passive for my tastes. There are lots of scenarios where clicking Plasma Fists, Taunt / Coaching, and Knock Off / Coaching are all useless and lose progress. It wants all four of those moves but can only fit three. Its biggest Coaching target (Shift Gear Genesect) is also not doing so hot. I do not believe offensive Zeraora was used once. Also doesn't appreciate the best Pokemon in the metagame resisting Electric. I wouldn't hate Zeraora in Tier 2 since a lot of people seem to like it, but I would make it Tier 3.
Zygarde: Tier 2 -> Tier 3
Agree. 14 uses, 4 wins, with one of them being a mirror match. 4 uses in Week 1, 3 in Week 2, 2 in Week 3, 5 the rest of the regular season. Imagine using Zygarde when you can use the two other best Pokemon in the format (Landorus is a much better Ground-type while Kyurem-B is a much better Dragon Dancer). It's also not a fan of Porygon2's revenge. This might actually see a come back with Nihilego, Zapdos, and Celesteela all being good right now, but it's definitely Tier 3 for now.
Tier 5 -> Unranked
All these Pokemon saw minimal to zero SCL usage and do not deserve to be ranked.
I would not be too opposed to Incineroar rising to Tier 1, but I do not want to nominate it myself. Tapu Fini is low Tier 2.
Rises
Landorus: Tier 3 -> Tier 1
Agree with the other nominations fully. This was the most restrictive Pokemon while building during my SCL experience, and I would definitely include it on any metagame survey the council puts out either when SCL or DWCoP ends. It's extremely powerful, fast, and even has a lot of cool options for its last moveslot -- Psychic is really nice for beating opposing Landorus and also 2HKOs Amoonguss through Sitrus Berry, Focus Blast hits Porygon2, Kyurem-Black, and Celesteela, Substitute creates free turns and punishes the opposition for trying to dance around it, while even Stealth Rock is viable. This was the second most popular Pokemon during the SCL regular season and forced Pokemon such as Celesteela and Zapdos to rise to try to check it. This should be an easy agree.
Celesteela: Tier 4 -> Tier 2
Agree. Meteor Beam Celesteela puts on immense offensive pressure with its dual STABs as well as Meteor Beam to hit would be checks like Zapdos, Volcanion, and Incineroar. Even if the surprise factor is gone, it's really easy to stack Special Attack raises with Meteor Beam and Beast Boost and eventually win the game. It's also one of the few things that switches into Landorus, although it must watch out for Focus Blast, which is extremely important. This is the best Steel-type in the metagame. 12th in overall SCL regular season usage, including an amazing 7/10 uses in Week 7. Also, don't run the Leech Seed set, it sucks.
Mew: Tier 3 -> Tier 2
I agree. Mew's versatility and reliable support prowess is very good. Fake Out, Tailwind, and Stealth Rock have always been great, but stax and Lunar. introduced us to the amazing Snarl + Will-o-Wisp set that can almost win games on its own at some points. It can do even more, including Coaching, Demon Mew, and even offensive sets with Expert Belt and Tailwind. It being one of the most reliable Tailwind setters as well as the new Snarl + Will-o-Wisp set has pushed it to Tier 2. Also sitting at 7th in usage for the SCL regular season.
Naganadel: Tier 3 -> Tier 2
Agree. Z Strats and I spammed this more than anyone, but I really believe it should be Tier 2. Dragon / Poison / Fire coverage is extremely solid, and hits like a truck when running Modest, which even lets it OHKO Metagross with Fire Blast. It's the fastest Tailwind setter bar Whimsicott and offers key resistances to Fire, Water, Grass, and Fighting. It checks a lot of boxes while building and matches up nicely to a lot of common Pokemon (Rillaboom, Landorus, Urshifu-R, Tapu Fini, Rain etc.) and is the premier Tailwind setter for offensive teams, but still works on balance and even Semiroom. I would definitely give this a try if you haven't already.
Zapdos: Tier 3 -> Tier 2
Agree. Another Platoon special, Zapdos is also underutilized. Great Tailwind setter (one of something like 3.5 viable ones), one of the few switch-ins to Landorus, matches up well into Urshifu-R, Rillaboom, Tapu Fini, and more, and hits very hard with Magnet set. It has some nice options for the last move as well, including Whirlwind, Toxic, Volt Switch, and Protect. Synergizes well with Landorus, Urshifu-R, and Nihilego as well. Hurricane is great, just hit. I wouldn't hate it staying in Tier 3, but Tier 2 is better.
Nihilego: Tier 4 -> Tier 3
Nihilego moment. This is a more recent trend, but I think it's definitely a strong one. Its 103 Base Speed is huge, outpacing the likes of Landorus, Urshifu-R, and two of the three most common Tailwind setters. Landorus' rise has seen a big decrease in Zygarde usage, while an increase in Zapdos which is a huge plus. Even Celestela gets 2HKOd by Meteor Beam into Power Gem while never OHKOing back, even at +1. Nihilego also matches up well into Landorus structures, and especially those which feature Zapdos as the Tailwind setter. It's also great into Rillaboom, Tapu Fini, Incineroar, Volcanion, Kyurem-B and more. In case you haven't noticed, I really think Poison is a strong offensive typing, especially when you combine it with something strong like Landorus, Naganadel, and Nihilego do.
Kyurem & Alola NInetales: UR -> Tier 4
Hail is pretty good. Ice is a pretty clickable offensive typing, and the playstyle has tools to play around Diancie / Metagross / Trick Room. We can even see in the SCL Replay that YoBuddy has Celesteela under Trick Room but it doesn't matter because he makes minimal progress due to Aurora Veil.
https://replay.pokemonshowdown.com/smogtours-gen8doublesou-584448
https://replay.pokemonshowdown.com/gen8doublesou-1423306761-iv0gtjbfhbnaga5ldbp47ijm6l6caobpw
Whimsicott: UR -> Tier 4
Prankster Tailwind / Encore / Fake Tiers is really good, especially with great beneficiaries such as Landorus and Naganadel. Great into all other offense besides Psychic Spam. Rillaboom is nowhere near mandatory so switching up your Grass-type is fine. Even after the disastrous start where Tailwind and Fake Tears do nothing, Whimsicott still wins the game with Prankster Encore.
https://replay.pokemonshowdown.com/smogtours-gen8doublesou-590454
https://replay.pokemonshowdown.com/smogtours-gen8doublesou-590466
For the past new nominations, we also have more testing replays against other SCL players, but I'll have to see if I'm allowed to share them. I'm also sure other players tested this during the season and have winning replays.
There are some other things I'd rank that other people used, but I don't feel like collecting replays so if other people want to do them please feel free.
Drops
Rillaboom: Tier 1 -> Tier 2
Do not think this has the splashability it had earlier in the generation, nor is it basically mandatory. Amoonguss and even Tsareena are both great options for Grass-types (Amoonguss especially was hardly viable during OSDT metagame, which also had Kartana which went excellently with Rillaboom), while I don't even think using one is needed at all. Both us and Nails + umbry only ran 3/9 Rillaboom in SCL for example. All its tools are still worthwile, but I wouldn't place it in the same tier as Landorus or Kyurem-B anymore. Rillaboom in Tier 1 would be okay, but Tier 2 is better.
Dragapult: Tier 2 -> Tier 4
Agree. This Pokemon is actually terrible. I have one Dragapult team in my builder that I never actually got around to testing because it had a Dragapult on it. If you want a fast Dragon-type, use Naganadel which also sets Tailwind and hits way harder. Dragapult hates Incineroar, Porygon2, Tapu Fini, and Diancie all being a lot better than they were during OSDT (and Kartana being banned as well as offense being downgraded), as well as most Rillaboom running Knock Off. Choice Specs Shadow Ball doesn't even OHKO Mew which is just embarrassing. This was actually brought eleven times in SCL, but performed poorly with a 36.36% win rate. Besides the game is won on team preview because Frania brought a team from last year's DWCoP, I can't remember it doing anything noticeable.
Genesect: Tier 2 -> Tier 3
Genesect is an unfortunate casualty of Landorus' rise, as the Landorus soft checks in Celesteela and Zapdos also match up well against Genesect. The rest of the OSDT -> SCL metagame shift isn't particularly kind either. This Pokemon was also used eleven times, but performed even worse with an unfathomable win rate of 18.18%, which is the lowest beside 0%. It saw 2 uses in Week 1, 2 in Week 2, 3 in Week 3, 2 in Week 4, and then a whopping 2 the reason of the entire regular season. It was able to do something productive once this season (Mishimono vs. Qwello Lee, Week 2), and it was its only win besides a mirror match.
Heatran: Tier 2 -> Tier 3
Easily the worst of the three main Fire-type Pokemon. Incineroar's support ability is unmatched, Volcanion thrives on Semiroom, which leaves Heatran seeing most of its usage on more offensively-oriented structures. 13 uses compared to Incineroar's 33 and Volcanion's 21.
Zeraora: Tier 2 -> Tier 3
Zeraora is often too passive for my tastes. There are lots of scenarios where clicking Plasma Fists, Taunt / Coaching, and Knock Off / Coaching are all useless and lose progress. It wants all four of those moves but can only fit three. Its biggest Coaching target (Shift Gear Genesect) is also not doing so hot. I do not believe offensive Zeraora was used once. Also doesn't appreciate the best Pokemon in the metagame resisting Electric. I wouldn't hate Zeraora in Tier 2 since a lot of people seem to like it, but I would make it Tier 3.
Zygarde: Tier 2 -> Tier 3
Agree. 14 uses, 4 wins, with one of them being a mirror match. 4 uses in Week 1, 3 in Week 2, 2 in Week 3, 5 the rest of the regular season. Imagine using Zygarde when you can use the two other best Pokemon in the format (Landorus is a much better Ground-type while Kyurem-B is a much better Dragon Dancer). It's also not a fan of Porygon2's revenge. This might actually see a come back with Nihilego, Zapdos, and Celesteela all being good right now, but it's definitely Tier 3 for now.
Tier 5 -> Unranked
All these Pokemon saw minimal to zero SCL usage and do not deserve to be ranked.
I would not be too opposed to Incineroar rising to Tier 1, but I do not want to nominate it myself. Tapu Fini is low Tier 2.