I've been laddering a lot in the past few weeks so I'm here to give my 2 cents on the metagame as a whole.
Rises:

from A to A+: this mon is just great rn, but I disagree with people saying it deserves S-. while I do think it's a premier defensive option in the current metagame and that his tool kit is absolutely insane, its over reliance on terastelization makes it far more manageable in my opinion. switching into salt cure is a pain in this ass, but seeing this on the opponent's team usually means it's the Pokemon that will tera at the end of the day, which gives the other player far more room to play around it. I think the biggest part of most games is figuring out who's gonna tera, and while this is one of if not the best tera user, knowing it's the one who most likely will due to his poor original typing makes it a lot less threatening in practice than it should be. on top of that, the metagame has been consistently adapting to it and makes it very hard for this mon to perform as well as it should on paper. still a solid A+ mon tho, cuz as predictable as it may be, it's still a pain in the ass to take down and leaves you a lot of room in the builder to contain threats that would beat it after it tera'd, but not anything close to being S-.

from A to A+: I don't see why so much people think this mon should drop. it's still extremely good, and while gholdengo being everywhere limits how much it can do, its access to u-turn usually just completely shifts the advantage into Gholdengo's opposition in my opinion. more often than not, the gholdengo player will find itself in a position where it just has to switch into corviknight to maintain hazards and it being able to just pivot out and enable a lot of breakers like meowscarada, chi-yu, dragapult, cb moon, chien-pao etc... makes it really hard for most gholds to switch in reliably all the time, leaving kind of a lot of room for it to defog at the end of the day. this mon just gives the player a lot of room in the builder thanks to how much it's able to keep in check in practice, and most people really underestimate that power. I don't this mon is any worse than it was in SS, and it will only get better and better if chi-yu/ape get banned in the near future (which should happen in my humble opinion).

from A- to A/A+: I think people already figured out why this mon is so good rn. in a hazard heavy metagame, magic bounce is such a great tool given that most form of "conventional" hazard control are just shut down by gholdengo. it's also in my opinion only second to garg when it comes to slow set-up sweepers. cm stored power / cm nuzzle sets are just way too good against balance, which we've seen a lot recently on both ladder and no johns. it being extremely potent against the big majority of hazard setters, and also a very splashable/reliable mon is what makes worthy of A+ in my opinion, but I could see it only being A rank for now.

from B to B+/A-: I think this mon was done dirty in the first slate. it's still a toxapex guys, and while it's more passive than it's even been, I do think it matches up well into most current top threat. recovery pp dropping isn't that big for it, as it wasn't really over relying on it thanks to regenerator, and it can still switch in and out to scout moves and send a more reliable answer. the metagame is currently shifting to a more balancey state and I think per is still one of the best mons out there for those type of teams. it can reliably switch in on locked chi-yu/ghold a few times, it's still one of the premier dragapult/valiant/quaquaval/azumarill/scizor/volcarona/iron moth/chien-pao checks, and it being one of the only mons with toxic make it a very interesting tool in and into bulkier teams.

from B to B+: this mons just a really good pivot and breaker rn. taunt boots and cb are getting a lot more exploration and the protean nerf with tera isn't as bad as most people think it is. flower trick is such a spammable move even into resistances, and it's access to taunt + knock + turn make it a really annoying mon for bulkier teams which as I said earlier is kinda where the metagame's states' at rn. this mon's a force to be recogned with, it matches up well into current trends and deserves a rise imo.

from B+ to A-: I'm not as convinced on this one, but I do think this mons' good enough to warrant a rise. cb sets snowball so quickly, and I do think it's the current best rain abuser we have rn. most teams aren't correctly prepared to face this guy, and playing vs it can escalate so quickly if you don't have one of dodonzo/amoongus/toxapex/(wa)clodsire which are clearly on the drop these days.

from A- to A: this mon's so much better than all the A- mons in my opinion. it's super easy to slap on teams and never disappoints in practice thanks to its insane type matchup into current trends. it's definitely one of the best pivots in the tier and definitely at least one of the most splashable ones. its lack of recovery hurts a little, but it's still really potent and doesn't struggle at all finding a position where it can enable the best breakers in the tier. scarf sets are also a great force to be recogned with as it allows rotom to keep in check most slow set-up sweepers (ape/hat/garg/sd hands/bulkyrona) and bulkier structures thanks to trick and to revenge kill some huge threats like chien-pao/chi-yu. outspending scarf gholdengo is also really cool.

from B+ to A-: this mons a bit underrated, it offers so much into offense/ho and is also really easy to slap on teams from my experience. it's incredibly hard switching into this mon, and just like rotom has a typing that matches up really well into current trends (being able to switch into chien-pao/valiant/espathra/meowscarada/baxcalibur at least once and being able to semi-consistently revenge kill dnite and roaring moon makes it a really valuable asset in my opinion to most offensive/bulky offensive teams.)

to A: this mon's a premier pivot, and sd is actually a really interesting tool with tera. cind does so much damage and actually has the speed to back it up (tying with moon is really good). but what I feel pushes cinderace into the A ranks is court change. this move is so much more useful than it was in ss because of how hazard heavy the metagame is. having cinderace transform into a normal type is also not bad, as it kinda forces the great ghost types (dragapult and gholdengo) not to use their normally super easily spammable ghost moves. fire spin sets are also really fun to use into more balancey teams, and although that's a lot more niche I thought I'd mention it as it's a set that was used in the past to some degree of success.
now onto some drops:

from A+ to A-: the ostrich demon struggles to find great opportunities to set-up and as eeveeto pointed it out well, relies a lot on tera/screens/shed tail to perform decently. it has low damage output, isn't that bulky, but I still think this mon's still able to get out of hand really quickly, which I why I think the A- drop suggested by Eeveeto is a bit too harsh. it still requires a bit of guessing games to deal with, and getting one turn wrong can make this thing go nuts extremely quickly. however, I don't think it's anything close to the other A+ ranks (probably baring kingambit) and therefore should drop imo.

from A- to B+/B: this mon is sooo inconsistent. it struggles to find openings, its dual stab isn't that great offensively and dnite/dragapult being everywhere clearly doesn't help it. its speedtier while pretty good is kind of annoying, as it doesn't outspeed that much for how "small-ish" damage it does and for how physically frail it is. it's also really hard to fit on teams, as it requires a lot of supports and pivots to make it work, and it's usually not worth wasting a spot when there are better fire types out there (chi-yu/cinderace/regular volc). I would advocate for a drop to B rank, but I could see people would want to keep it a bit high as B+, cuz a pivot with tspikes that does a lot of damage is always cool to have into the bulkier trends of the metagame.

from B+ to B/B-: I would honestly consider just swapping this guy with pex cuz its not really useful into the current trends. the tier being filled with super strong dark and ghost types usually forces slowking to tera to remain a useful piece of a team, which is something you want to avoid as much as you can while building as the mindgames offered by tera are quite unique and a big big part of how the current metagame plays. future sight/pivot isn't nearly as good as it was in ss, and slowking's niche suffers a lot from that. add that to the fact that it simply doesn't have a lot to keep in check as most special attackers just outright beat it and force it out and you just have a mon that becomes really niche at best.
other noms I agree with, but I don't have time to elaborate on them (will probably make another post when I have more time)

keep in C

to A-

to S-

to A

to UR