Here are are my metagame predictions.
:gholdengo: Gholdengo
I will address the elephant in the room right away. Gholdengo will need to go. No Boots is already grounds enough to justify a Gholdengo ban, but it goes much further than that. Not only did I hear from a close source that Defog Corviknight has reportedly filed for a McDonalds job application, we have a grand total of zero (0) Defoggers that come even close to being able to maybe beat Gholdengo. Talonflame gets OHKOed by Rocks so it does not count either. This will shift all stocks from Defog to Rapid Spin. And by that I mean Excadrill, because it is our only Spinner that immediately threatens an OHKO on Gholdengo. Quaquaval could work maybe perhaps (it won't) but then you need to Knock on the switch, which gets weakened by Colbur, then... idk, just flail around ig. So yeah, Excadrill is the only option. It barely works too, we've seen the interaction in ZA-OU, and usually you need to click EQ on Gholdengo or look like an idiot trying to read a switch, in addition to taking a Focus Blast to the face, which is piss easy to take advantage of. And the cherry on top comes with the next mon I will talk about.
:annihilape: Annihilape
Even when I first saw the nerfs, I figured it would still be broken af. Taunt/Bulk Up/Rage Fist/Drain Punch is simply too much. Its answers are not necessarily super limited, but this is the perfect example of a mon that you cannot outplay. You either have one of its defensive answers (it's only Clefable) or a fast Psychic, Ghost or Fairy special attacker. If you do not have one of those, you lose, period, no questions asked. This is obviously extremely restricting for any playstyle, including all flavors of HO. And to get back to the hazards problem, let me ask you a question: Why would you run Defog in a Boots-less Gholdengo meta where no Defoggers beat Gholdengo? That's right, you don't. So you don't even need Gholdengo most of the time and can run only Annihilape, who just so happens to be tanky, spinblock, outspeed Excadrill, and can OHKO with Close Combat or do like 90% with Drain Punch and heal back to full. Getting rid of hazards is so impossibly difficult and you have to spend so many resources to manage to do it that you usually already lost when Spin actually worked. Oh and about the Rage Fist nerfs, yes it did nerf Annihilape, and no it is not enough. Remember, it only takes hitting in once on the switch and it now has a 100 BP, 100 Accuracy, no downsides physical Ghost STAB. What? Not to mention how it still very much synergizes with Bulk Up and Drain Punch.
:light clay: Light Clay
I expect Screens to be way too strong with Light Clay around. Sure, the early meta will be HO cheese spam no matter what, but it does not change the fact that it's going to be stupidly strong. Grimmsnarl is the most perfect Screens setter, having priority Screens+Taunt and being immune to Prankster Taunt itself due to being a Dark type. There is no way to prevent Screens from getting up, and from there, be ready to be assaulted by the most inhumane things like Contrary Close Combat Mega Staraptor behind Screens, or Ceruledge behind Screens, or what about Mega Charizard X behind Screens? Oh, I have a better one: Mega Blaziken behind Screens. yeah no, there is no way this is fair.
:swampert-mega: Mega Swampert (and Rain in general)
It's hard to tell what directions Rain will take. On one hand, you have Mega Swampert with its newly added Wave Crash for your Rain abuser of choice. On the other hand, Mega Meganium is still great in Rain... probably. Rain will definitely peak super early on and slowly settle to an "offense archetype you have to respect" place. Ferrothorn not being in the game does help, but you still have to deal with Sinistcha who's even worse to deal with for Swampert... But that's kind of the only defensive answer? Wave Crash recoil will very much be the only thing keeping it in check. Regardless, Rain still has to deal with Glowking resetting the weather every other turn as well as hazards.
:blaziken-mega: Mega Blaziken
I will use my gamer™ instincts to guess that it probably needs to be banned. Regular Blaziken could be fine depending on how popular TankChomp is in this new meta? I mean, it has to be UUBL in SV for a reason.
Mega Staraptor (and everything else that is even remotely strong tbh like Mega Raichu Y)
While it is no doubt very strong right now, you also have to take into account the fact that teams have to make 17 concessions and a half to not autolose to hazards, Annihilape, Screens HO, and Rain right now. I can only hope Gholdengo, Annihilape, and Light Clay are dealt with asap so we can properly gauge these moon's strengths in a 6v6 format in a metagame that makes sense.
:hatterene: Hatterene
I also predict an even higher Hatterene usage in response to hazard removing being effectively too difficult and costly to pull off. Pretty much any team that is not pure HO will require Hatterene to function, ESPECIALLY if running Rocks weak mons like Volcarona.\
Mega Dragalge
My underdog pick. When the first bans eventually happen, it will be a great glue to play around things like Volcarona, Floette, Mega Raichu Y, Mega Meganium... It won't be perfect, but I hope it will at least manage to check enough boxes to warrant a slot in serious teams.
The Frauds: Mega Eelektross, Mega Sceptile, Mega Falinks, Mega Barbaracle
The frauds. They're frauds. Do not buy stocks from them.
I'll talk more about the tier when the first wave of bans happens. Even if the council is just as terrified as the SV OU council at the idea of touching Gholdengo, at least I know Mega Blaziken will make something, anything happen, and so I will keep huffing my hopium.