Just a few ideas incoming. It's been a while since I posted and there's some stuff I'd like to address. Hope you guys enjoy reading! :)
Rises
Froslass C- -> C+/C: Froslass Spikes has received a lot of exploration and proven success on ladder in recent weeks, and I think that its strength as an archetype would be better reflected by rising Froslass to be above a fellow Spikes setter in Roserade or at least alongside it in C. Froslass's unique tools all come together super nicely for it to function as arguably the most reliable suicide lead the tier has to offer. Between its Ghost-typing, Taunt, and STAB on Ice-type attacks, it can very easily deter attempts from a lot of popular removers, like Hydreigon, Empoleon, Gligar, and Starmie, to remove its Spikes. Destiny Bond is also a massive boon that if played correctly, can allow you to permanently prevent the opponent from removing hazards if used against a foe like Rotom-H or Hydreigon. It also has a lot of utility as a solid way of punishing Pokemon that think they've been invited in by Froslass for free setup, like Bisharp and Terrakion, and is a decent tech alongside Icy Wind for taking out stuff like Zeraora and scarfed Krook. Overall I just think that this thing has a lot going for it and can currently capitalize on its several handy tools really well in the metagame, and this has been reflected by its more frequent inclusion on a lot of HOs in recent weeks.
Drops
Hippowdon A -> A-: Hippowdon still does its job well, but I think that a drop is appropriate right now considering that it isn't so much the premier defensive Ground-type it used to be. Gligar, Nidoqueen, and Palossand have all received a lot of recent exploration that has earned them more inclusion on Water-/Ground-type cores often seen on balanced builds, giving Hippowdon a fair amount of competition and more heavily pronouncing some of its shortcomings, like being a shakier answer to Terrakion and Zeraora than the aforementioned Pokemon. With moves/abilities like U-turn and Sheer Force in their arsenal, some of Hippowdon's competitors are also more well equipped to punish or at least maintain momentum against a lot of common Ground-type switch-ins, like Hydreigon, Latias, Togekiss, and even Rotom-H, which despite having a shakier matchup than the other listed examples, partially eats into Hippo's niche as well as a relevant Electric-type that can more comfortably take it on through proper prediction and tech than, say, Mega Manectric. Right now, while still great, the recent rise in Electric-types more capable of taking Hippowdon on alongside the niches its increasing competition can edge it out with in some scenarios makes A- reasonable in my eyes.
Suicune A- -> B+: Suicune still has the potential to be a really annoying Pokemon for a lot of different archetypes to deal with, though it's felt a lot more outside of the metagame than placement in A- would currently suggest. Mega Slowbro has given it a healthy amount of competition and proven more worthwhile in some scenarios due to the perks of Regenerator pre-mega and simply being a better check to a wider variety of meta-relevant threats. Celebi gradually occupying more of a space for itself in the last couple months, Zeraora's introduction, and a lot of other Water-types, like Tentacruel and Empoleon, proving worthwhile in tournament play has also eaten into its niche some. While I'm not totally sure on this change, I just don't think Suicune's current relevance and teambuilding impact is reflective of where it's ranked when compared to stuff like Infernape and Kommo-o, especially considering its pretty lackluster usage in most respects.
Rotom-C B+ -> B: I LOVE me some mowtom and it hurts me to have to nom it down, but right now I don't think the meta favors it very much. Rotom-H provides it with a lot of competition and generally provides more meta-relevant niches that Electric-types are fitted on teams for these days. Heat's typing is just more applicable in a metagame where Flying-types, Scizor, and Mamoswine are all fairly important for offenses and balances to fit checks on their teams too. Rotom-C's biggest niche as an Electric-type, its ability to punish Grounds efficiently, is also less relevant now that Hippowdon is really the only common Ground-type it can take advantage of super reliably, given that Gligar, Krookodile, Nidoqueen, and Mamoswine can all punish it to varying degrees of success. It just feels like a less reliable pick with niches over its main competition, Rotom-H, that simply aren't as advantageous as in metagames past. A drop sounds due.
Talonflame B- -> C+: Big Linda adequately takes advantage of Scizor still, but I don't really know what else it has going in its favor for B- to be reasonable anymore. It really struggles doing anything of worth to either Slowbro form, doesn't put up well with Rotom-H and Zeraora being popular picks, faces more opportunity cost in a metagame where Moltres is a consistently strong pick, and struggles for setup opportunities more than in metagames past given that it doesn't take advantage of the tier's pool of top threats nearly as well as when Breloom and Serperior were around. I still think it can be a deadly sweeper under the right circumstances, but those circumstances have become harder for it to achieve and it's had generally lacking usage for a long time now. I think it's fair ranking it alongside stuff like Feraligatr and Cofagrigus.
Metagross C+ -> C: This guy really struggles for a niche and its weaknesses that were already present in the metagame have been further compounded by Bisharp coming down. It both competes for a teamslot with Bisharp and struggles to perform any of its designated roles as well with it in the tier in general. Overall its lacking power, continuous struggle to find a definitive niche, increasing competition, and general awkwardness is enough for me to believe that not even C+ accurately represents how mediocre and hard to justify it is in the current metagame.
As far as some other opinions people have voiced in the thread go, I really don't think now is the best time to drop Chesnaught. The arguments brought up in favor of lowering it were fair but I still think Chesnaught Spikes builds have a lot of merit due to the utility its typing and moveset allows it to provide in nearly every matchup. Zeraora and Bisharp are still very important parts of the metagame, while checking other present threats in Krookodile, Crawdaunt, Sharpedo, and a decent amount of Scizor sets. It maintains solid general matchups against a lot of different popular archetypes and its utility still has the same value as when it rose to B+, so for now I'd wait to see if meta trends disadvantage it more than they do since I don't know that anything's changed enough for dropping to be fair just yet. Stakataka is meh right now and really shouldn't be in the same rank as Aggron, and Mienshao's niche has definitely become well pronounced in this metagame but B is the highest I'd raise it since it still runs into issues regarding its matchups against bulkier builds and prominent stuff like Togekiss and Altaria.
That's it from me regarding VR stuff! I'd like to close by just saying that this is my 500th post on Smogon, and I'm really grateful for some of the things this site has done for me that I really wouldn't have ever thought it would do. Don't wanna make this post much longer and wanna try keeping this relatively short and sweet so imma acknowledge some people in a hide box: