Not a single pokemon gets Dragon Dance if the learn sets are accurate.
M-Charizard X is going to have a bad time without Dragon Dance, Dragon Claw, and Tough Claws. I could see maybe a bulkzard being run since he still has roost at least.
Clefable is going to be in a weird spot. Losing Unaware hurts, but she has pretty much no competition as far as other fairies go. Mr. Mime and Wigglytuff don't offer much, and A-Ninetales misses Aurora Veil.
The meta here is going to be very bulky and very special focused. The lack of Dragon Dance, poor Swords Dance and Bulk Up distribution, no Choice items/life orb, and abundance of bulky mons with healing options leaves me thinking we're going to be seeing a very slow and bulky meta. Not to the extent of gen 2's, I'm sure, but it definitely seems prevalent. Actually, even accounting for Bulk Up, Calm Mind, and Quiver Dance (though the last has really poor distribution anyways) means adding more to defenses anyways. If candies really do add +200 to each stat as well then bulk is going to outpace damage on top of all that.
Melmetal is almost definitely going to be OU. The thing holding him back I think will be the lack of recovery options. Many teams will likely be packing fire blast anyways, which is going to hurt bad. He's probably thankful for the lack of hidden power, focus blast, and earth power (for now, no clue how much those will come in through Go).
I think A-Marowak is going to be a stand out in LG. The loss of Thick Club sucks for sure, but being one of the only decent Swords Dance user and the only one immune to burn is going to be a very big point in his favor. The major issue he's got to deal with is not having a single physical ghost move to his name. Not even a physical dark attack either is painful.
The lack of weather moves is... odd. Weather was already going to be extremely niche without the abilities or items needed to actually make it viable, but Growth users are really going to miss it. I think if they'd been in we would have seen some niche grass teams utilizing it for quick massive boosts.
Mewtwo is heading straight for Ubers obviously but it's a long way from gen 1 and even M-Mewtwo X and Y have some checks but nothing that can handle the sheer versatility and power he brings. Even M-Gengar speed ties at best. Outside of that maybe an SD M-Pinsir can hit hard with X-scissor if he's lucky? I'd say having Fire Blast on Mewtwo is going to be common to deal with the bugs and Melmetal. M-Gyarados can hit hard but Mewtwo still outspeeds and packs T-Bolt and Brick Break. Bulky M-Zard X will take neutral damage from most of Mewtwo's common attacks but will still likely get 2HKO. Weirdly I think the biggest threat to Mewtwo will be Mega Beedrill, who outspeeds it and hits hard with bug attacks. It probably wishes it had a flying attack for X, but then, it can't do much to X before getting OHKO'd by it. Anyways the point of this whole paragraph is that Mewtwo remains as powerful as ever.
Dragonite sits in a sad spot right now. No Dragon Dance. No Multiscale. Poor movepool with only Outrage and Wing Attack for STAB. I think sheer stats will keep this guy in OU but with Stealth Rock and ice attacks being abundant, I don't know how useful he'll be.