I think you guys are all jumping the gun
far too much.
We are about to get plagued with an incredibly chaotic, arguably even more tumultuous meta with the incoming returns of many top OU threats, many of which are banworthy in their own right. It is absolutely not the time to be discussing possible unbans of other Pokemon to make things even more chaotic, especially when we have no valid grounds to test these claims when the meta that we know right now is very likely about to radically transform in an instant, no matter what is ultimately quickbanned or suspected. In other words: there is
no way we can tell if anything will be broken or not, and it's not at all the time to speculate on if things (especially Necrozma Dawn Wings/Zamazenta, no less) should be unbanned in a meta that we can merely only speculate upon for the meantime.
I feel most of the propositions being made seem good on paper due to their performances and weaknesses in Ubers, but frankly, these do not work as arguments either. It's important to consider that the Ubers metagame is, at its core, a playable banlist, and that their execution and downsides in Ubers are at their core negligible and meaningless since it's meant to contain them from a metagame that otherwise prioritizes balance.
If I'm honest, I feel we should be looking more at what unbans have been already made, and in what ways they'll fare in the metagame. I'll start that discussion:
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I think Landorus is still gonna be far too much, especially with the loss of Hidden Power to check it more readily on the Special side. The metagame, defensively, is not really equipped to take on its gauntlet of Sheer Force-boosted coverage, and I'm definitely for trying it, but I imagine it isn't going to be lasting long whatsoever.
genesect funne u-turn moment go brbbrrntntnt
Blaziken, to me, is the most interesting case. Although I feel it will still definitely be broken, I'm intrigued to see how it will fare in a Toxapex/Landorus-T infested metagame without Z-moves and Hidden Power Ice. It does have access to Close Combat, which is a definite improvement as far as Fighting-type STAB goes, though I feel Earthquake + Fire-type STAB holds a bit more ground in terms of neutral coverage. It'll be interesting to see, but I think it'll still be too much.
Zygarde is another odd case, as losing Z-moves really annoys it. Though, the Dexit and HP Ice's removal also really helps it out defensively, giving it more profound setup opportunities. I can imagine Sub + DD will be particularly strong, as Tangrowth will likely become setup fodder as opposed to a once reliable check. I think it has a shot, but I think it overall improved from last generation due to these indirect defensive buffs.
The gain of Close Combat alleviates a lot of the risk involved with High Jump Kick and gives it a much more reliable Fighting-type STAB, and as an offensive pivot, it absolutely
loves Heavy Duty Boots. It isn't really hurt by the Hidden Power loss, though, as it still has access to Ice Beam to throttle things like Lando-T and Zygarde, which I think will almost always be run. I think Phero will still be too much as well, though.
This thing wasn't busted before imo, and with the return of Zapdos and co., it will undoubtedly be fine in my eyes.
I'm admittedly kind of mixed on these two, but I think Magearna could possibly still be too much with its still unmatched set versatility and execution.
Though, Cinderace is fairly annoyed by the additional options in the metagame to interfere with its pivoting shenanigans, so I think it will
probably be ok. I think Cinderace's Bulk Up set is probably losing viability due to Landorus-T's return, leaving U-Turn + 3 Attacks to become by far the most superior set. It'll be interesting to see how these two fare.
With the return of Lando-T, Zygarde, and Garchomp, Ice-type coverage is now pretty important again, and I think we'll be seeing the impacts of Hidden Power's removal a lot more in this coming shift as well. I can imagine things like Slowbro coming back into prominence (if the Tapus get eliminated) sometime down the line partially for this reason.
Overall, though, I'm super excited for these shifts, and I cannot wait to experiment and see what ends up shining!