Hello! I'm supposed to be packing for a trip and doing the dishes, but instead I feel like writing out my day 1 findings. I am going to go over the new drops first, highlight some of the mons we already had, and finally what I think is going to fall off. For context: I have not made a team with every new mon yet, but I have faced or played with every mon that I will mention.
New Drops

Stall players rejoice! You now have a great Sp. Def option that will not get instantly owned by spikes! The downside for the play style (not to even mention the amount of taunt mons available) is that it is still extremely easy to fit knock off on your team and excadrill runs your pockets (unaware mons shaking in their boots). Having access to rocks is very nice to free up your ground type move pools, thunderwave can be great for a more balance team approach, and it being the only real mon that can access heal bell makes it great glue to any fat team. I expect to see it a lot tbh as it does quite well to block most Sp. Atk users, and the ones it needs help with are easy to account for. Maybe one day I will become evil and load it up on ladder but until then hf and pray you don't run into taunt users.

I already defended GOATSIRE in the uu cord, but this mon is gonna be OK ! I think we will be able to find some really neat sets for it to where this thing will be some form of a mix wall, toxic spreader, and either unaware sweeper stopper or water absorb cuck beast. I do feel like it has very big downsides in the fact that it gets walled by skarmory and balloon steel / poison types, but those kinda all fit into the same category of coverage to build around imo. I think this thing will have a slow start but will end up being a B- to B mon on the VR the further into the meta we get.

Having a good fire type is pretty sick. Ability flexibility depending on wanting to make certain mons think twice about clicking u-turn or wanting to win the heatran 1v1. Magma storm trapping with taunt being a huge issue for the 3 new stall mons we got, and also access to rocks makes this mon great glue for any team. Gonna be high VR and I think we will see it in most styles of play.

My king has finally returned....... goated ass mon. Has some new troubles that it didn't have in the SS days, but still a great glue. Access to spikes makes stacking so much easier while also letting you run more offensive ground types (EXCADRILL EXCADRILL EXCADRILL). I have this thing soft checking serperiors and hydrapples too. Rocky helmet feels great and tera ghost is a great backup option for gettting chipped down vs okidogis. Keep this one on your radar its a meta shifter fs.

Honestly when I saw it was gonna come back I was thinking to send it to the shadow realm ASAP due to a lot of the old meta team setups. But actually I think its fine. Our bulky waters and steels do a great job dealing with it to keep it in control meaning you have to at least position right to get the late game sweep off imo. It'll be a great offense mon but not a must bring for the style imo. Great knocker too !
Still Around / Rising Stars

This mon is still strong as hell. CC chips skarm extremely well for a physical mon, choice scarf gunk has put me into positions where I just threaten an entire team a handful of times, and the respect the oppenent has to give a lot of the time makes for easy doubles. I dont think this mon is going anywhere soon and is probably still one of our top dogs.

Goated mon rn. Spreading will-o + pivot feels unbelievably good. Easy to pain split a lot more now too. Pairs great with heatran as always. Not much to say as the set hasn't changed much other than it being a great electric option to replace zapdos. Keep an eye out for this mon.

Think this mon is going to be a lot better now with Zap gone. Torn is still great and threatens sini a lot, but skarmory or other flying types have more abilities to replace torn on teams now, making sini have one of its checks a bit less prevalent and the main one completely gone (tera on this mon is always great too). I think the meta is going to get a bit fatter to deal with some of our strong attackers now that we have the tools, and the last time I felt the meta was like that Sini was always great to have around. I expect it to keep getting better and better with these shifts.

Man this mon is surprisingly annoying for how I want to build rn. Tanky as hell mon that a lot of the drops kinda struggle with on top of the team structures around them. I feel like if it brings the right tera it will just claim half your team. More offensive builds with EP are definitely viable too right now with heatran running around and the slight drop in some speed tiers on certain teams makes it work well. Its also great at stopping okidogi from doing its thing which can give a lot of opportunities to get some mileage off. Overall probably a bitter better of a bring now (even though it was still good before shifts)

Putting this one last cus I'm sure a few eyebrow raises have already happened before anyone started reading this section. Magneton is not only good/viable, but it is also better than magnezone. Magneton is a great enabler for our main offensive drop Weavile on teams. Choice scarf outspeeds and threatens all of our fast mons in some way, shape, or form and can make up for damage loss by being paired with our plethora of regenerator pokemon that would be carrying an eject button. It is the same idea from SS days (who woulda thought since we have all the same steel types), except now you can also threaten excadrills with tera ground / fire / water / fighting. I am personally a tera ground fan as you can also have a lot easier of a time trapping heatran and can catch pokemon like sandy shocks or pokemon that like to tera electric (serperior) or steel (hydrapple) off guard. Choice specs variations can also still run modest while outspeeding and killing offensive scizor spreads while threatening bulkier pokemon (usually tera'd bulky pokemon) better. I understand this is a bit of a gimmick at first glance, but the steel types / tera types are a very important glue in this tier imo. Having a pokemon that can reliable disrupt their plans in order to release strong attackers the tier has access to (weavile, latios, hydrapple, scizor, etc.) can be extremely valuable to have. I recommend you go try it yourself and see if it brings you success as it has for me on day 1.
Send to Shadow Realm

Suboptimal glue mon became more suboptimal today imo. Having access to toxic and knock is great, but usually has 4mss with trying to control hazards or foul play setup mons so your team doesn't lose to the one mon it's weak against. I think other mons are just able to prevent sweeps better or remove hazards better rn. Better knockers in TTar or weavile, and better toxic users in Toxapex, Clodsire, and poison touch okidogi (this counts). Expect to see less and less of this hopefully it gets good RU usage.

A lot less reliable of a ground type now that it isn't able to annoy zapdos. I do think an offensive set has some potential on certain teams with substitute + para spam or rock polish + spikes, but overall it is going to need to be reimagined. A quick look at the VR says B+ right now and I think it's easy to say thats a quick step down.

Better ground flexibility for offensive mons + skarmory gap + weavile drop + no roost + early 2010s tongue in picture pose + i don't like this mon anyways. Cool that it has u-turn and toxic I guess (and can't get toxic'd) but I would rather use anything else.

Think cornerstone will still be fine, but I think ogerpon feels a little lost rn. It is probably still a great encore + knock + pivot option, but I think finding the mileage it once did could prove to be a little hard. Maybe I can pair it with skarm trapper and it actually goes hard still but I haven't been impressed when I see it.

It was cool this thing had viability, but I kinda think it will struggle into a lot of the main walls now. Maybe it can get its chance still but I think the set is either going to be tera reliant / have 4mss now to maybe fix some mu issues.
Thank you for reading if you made it this far! I actually had a lot of fun playing the meta today I havent enjoyed the ladder this much in a long while. I think the meta development rn will be very good and I think if I just play it when I feel like laddering I will have a great time. I'm reading through all the other posts right now as the takes have also been fun to read. Maybe I will make an update in a month or so and we will see how things have changed lol.