(Thank you stef ^^)
You're right in that it could be a gen 6 hack, but that is a LOT of effort to put in for just a couple of leaks. And it wouldn't be the first time a tester leaked info based off the beta version of the game. Persian mainly being a simple recolor almost gives it more credibility, since that's honestly all Alolan Meowth is.
Wait and see is still the name of the game for me.
I think this is a hack, look at this trailer minute 2:03
you can see the Pokémon summary is different