Most of this relies on Venusaur staying UU (which it totally should by the way), so keep that in mind.
Discussion Points:
A+ -> A:
Disagree
Togekiss is able to adapt to pretty much everything the meta throws at it so I don't really think in my mind it would have ever dropped unless Diancie stayed. It appreciates being the only Fairy that can threaten Venusaur offensively, and has sets that really catch rising stuff like Mane and Spikes offense such as its Offensive Scarf set.
A -> A+:
Agree
Was nice not having to see this annoying shit as much, now its back and pretty equipped to beat its usual counterplay. Yes hippo is getting better, krook is getting better etc, now that it doesnt need HP Ice it has room for a lot of cool options like Toxic and Signal Beam (this catches Lati Drei Krook Celebi in one slot its pretty cool) that will smack usual checks, and makes it something you have to scout for beyond whether it was running HP Ice or Grass.
A- -> B+:
Disagree
Still splashable for how useful defensively its typing is, Ghostium sets have started to make waves and really catch teams where the ghost resist is going to be a Krook (happens a lot because of how well krook pairs with venu), still will be useful in basically all matchups.
A- -> B+:
Agree
Still a fine mon but awkward to build and Suicune is generally more consistent vs everything but stall, I do think this receives a little less usage than it should though.
B+ -> A-:
Agree
Spikes rock with stuff like Mane getting better, Mamo coming back, and being able to set them up on Venu and force in the hazard removal so you potentially trap it. Defensively has Mag Rise to also function as a great check to opposing Mamoswine, something you always need.
B+ -> B:
Agree
Another Volt Blocker that can Ice Shard it makes it want to click Leaf Storm more, Venusaur and Amoonguss walling it eternally unless you're running a gimmicky Z-Dream Eater set, meta changes weren't super kind for mowtom.
C+ -> B-:
Agree
Can come in on Venu to rock, I think mixed sets get better just by virtue of people expecting some form of Rocks / Meteor Mash / Zen Headbutt on every set now and they won't be as obvious as they could have been in the past. Can run Shuca to make a nice Mamoswine lure.
Other Noms:
Keep Unranked
Switching into Venu isn't enough to warrant using this, its horrendous speed tier lets so many threatening breakers in even when it picks up a kill, every Steel comes in on it pretty reliably except Cobalion which only comes in once, it gets trapped by Krookodile which gets run with Venu a ton. Don't think its worth using this over other breakers like Drei and Kyurem.
C+ -> B-
Reuniclus likes some trends towards these Fat Venu Balance and Bulky Offenses, I've been using a physically Defensive CM set with Life Orb Psyshock and Energy Ball, you can do cool stuff like Recover on Krookodile Pursuits (and even Knock Offs from full if you mispredict), if you get caught switching out it only does half. Obviously is super handy to have vs Stall, pair with something to chip the Steel and you're in business. Pivots into Venusaur relatively cleanly, takes a decent chunk from Sludge Bomb but thanks to Magic Guard doesn't have to worry about Poison or hazards and can recover it off. Common Rockers like Hippo and Pert can be setup bait, overall just some nice trend
A- -> B+
Really just isn't nearly as kind of a meta as it had when it first was UU. The centralization of Venusaur means that most teams will be packing both strong Flying- or Psychic- breakers that can dent it, as well as even lures that attempt to catch Venusaur unfortunately hitting the poor mushroom as well. Still has a nice niche since you can build it with other great Megas like Aerodactyl and Spore is a valuable tool, but Venu's titanic bulk and offensive prowess overshadow it.
Unranked -> C-
Rank this, its funny to have an actual Terrakion counter exist, getting Rocks means its not just a dead slot on a team, can even run Colbur to mitigate Pursuit weakness once without it detrimentally effecting it from walling what it needs to. Shore Up taking advantage of Hippowdon is kind of funny too, as well as Water Compaction actually being useful solely for screwing over Aqua Tail Aerodactyl. Fun mon that has a small niche, let it on the board.
edit: forgot kommo its good as shit rise to A-