My opinions on viability post shifts:
Starting with the S rank, then moving down.
S Tier: The best in the tier at the moment. People prepare really hard for this guy but its consistently excellent through using trick, coverage, and bringing in teammates to overwhelm its dedicated check.
S Tier: Similar to munkidori where people have begun to prepare a lot more for it with the likes of bellibolt, houndstone, and slowbro-g but it still shreds. Its also underrated as a great knock off absorber for non-removal teams to keep boots on everything. A trait which is quite unique especially with gastrodon's departure.
S -> A+: It has been dethroned in my opinion. DD sets are very dangerous as it has at least neutral coverage for everything. Some of its other sets however (namely scarf) have fallen out of usage. There's also a new ground type which competes with it.
S -> A+: Still an amazing wincon with many sets that leave the player guessing. Despite that, its seemingly awkward to build with in my opinion. The main reason why I think to drop it is because there is a new rock type which competes with it.
A+ -> S: I think it deserves it. It honestly shapes how the tier behaves a lot. There's an abundance of water type offense for it to check. The many strategies people have come up with to try and abuse it also demonstrates its presence, and despite them, it consistently performs. Its also very easy to build with, and is a staple on balance. Heck, there is even a whole speed creep meta that was built around vaporeon, with mons such as diancie, dudunsparce, scrafty, hariyama, incin, rhyperior, and many more all wondering how much speed they should run due to how crowded vaporeon made the 167-180 area.
A+: I can see it being S in the near future but I will settle here for now. Incredibly strong and has all the coverage it needs. Also difficult to take down, and can often go 2 for 1 especially with tera.
A+ -> A: Tera blast puts rhyperior on its toes, but it now ideally has to either give up a slot for tera blast or run u-turn instead of volt switch because unlike gastrodon, rhyperior is not the mon you want to consistently give momentum. U-turn brings down its damage output quite a bit, so it drops for me.
A -> A+: Honestly might be the best steel right now, definitely the most common steel I've seen in recent days. It can effectively trade vs offense teams due to its higher damage output than zong, who often gets overwhelmed. The damage, knock, and phazing utility also helps against much of the bulky setup we are seeing now (which zong and especially keys can be fodder for). Also, I find AV to be heavily underutilized, the damage is crazy and it has coverage to beat the ever-present tsareena which zong often falls to.
A -> A+: Best special breaker in the tier. It restricts balance teambuilding so much with how few reliable switch in options exist. It makes building around it very flexible too. I've seen a lot more physical basc these days, pointing to how uncontested chandy is in its role.
A-: Strong pivot, I think its a healthy addition. I think basc is more versatile, and ironically choice scarf wave crash on basc is stronger than banded liquidation. Anti-rain, coverage and natural speed give it niches.
A- -> B: Outclassed as a regenerator mon by slowbro-g, and as a grass type by tsar, loom, and wo-chien. Its drop to pu reflects this.
A- -> A+: Honestly has so much it can do. It can serve as a special wall, status and knock absorber, and wincon. Both bulk up and dd+encore/taunt sets are extremely good right now. No more direct competition for its role with muk gone too.
B+ -> A: What a turnaround she has had. Best removal in the tier due to its defensive sets; its usage in NUPL reflects this. We're seeing hazard stack teams with spinblockers via houndstone or tera ghost more now. Teams which are literally designed to abuse tsar shows how good it is now.
B+ -> A-: Second best removal for balance teams. Tsar on average accomplishes more in my eyes, but in certain matchups alt has a higher ceiling by being very difficult to take down. Defog also bypasses the spinblock teams. It feels both passive yet difficult to switch into at the same time due to wisp (and the rare trap). Like tsar it is comfortable switching into and sitting on most of the common setters. Losing boots on it isn't the end of the world for this reason.
B+ -> B: It can't switch directly into as many setters as altaria and tsareena and doesn't like losing boots, so its a niche pick on balance teams now. Its a staple on stall though.
B+ -> A-: Personal bias aside A- is probably best but I can see it go as far as A. Insane longevity and Its quite unique alongside scrafty and sylv/vap as a wall which can also act as a wincon. Iron press sets 1v1 any bulk up shenanigans while being a great wincon in its own right. Calm mind sets trade the 1v1 ability but can become even tougher to take down while being oblivious to burn. AV sets are also seeing some use now due to its ability to check munkidori while also providing immediate power and amazing coverage. Its biggest downfall is ironically the shared typing with munkidori.
B -> A-: Combines some of the roles of our departures muk and gastro. Its very annoying to face, and has the ability to set up multiple layers of spikes and do a lot of chip. SD sets are also underrated in my opinion.
B -> A-: This is up there for one of the best setup cleaners in the tier. Its more team specific by virtue of having fewer defensive traits but you're always pressured to keep the one strategy you have alive to defeat this, if you have one.
B > B-: In some games its great but its so high maintenance, requiring removal, and safety from knock and status. Bulky setup also destroys it and is much more common nowadays. These factors and its lack of resists make it hard to compress into the teams its supposed to be on.
B -> B-: Its signature curse set has another check in rhyperior and honestly I have not seen it much even before rhyperior got added.
B - > B+: Toxic, slow pivot, static, and recovery are all very nice. With water coverage it can trade with rhyperior so I don't see it being that problematic. If anything it appreciates muk's departure.
B- -> A-: The physical version of dudunsparce. Scrafty is overall more useful but its a pimp when faced against breloom. The grass type slot is heavily contested by tsareena and the defensive stats are a let down at times but it gives you the same uneasy feeling as dudunsparce in team preview. Has won many games on its own in my time using it.
B- -> B: I am seeing it more often, mainly the specs sets which are very strong and have tools to take advantage of steels. Ghost resist is very valuable in the builder.
B- -> B: A staple on those hazard stack teams I mentioned. Torments teams that rely heavily on tsareena.
B- -> UR: Goodbye
C -> B-: It requires a lot more support than the top steels but its a great tank with power, bulk, and speed. You often have to accept trading with it.
C -> B-: Its a good progress maker with knock, toxic, strong stab and coverage.