Any Poke that got changed into a Fairy-type in Gen VI is banned, since we're playing in XY OU and there's no way to remove their typing on any of the simulators to my knowledge without playing in a previous gen, but then you don't get to use Megas or anything else Gen VI brought us.
Right now we're sitting at 119 entrants. I'm going to wait until tomorrow afternoon (I'd do it in the morning, but I have a doctor's appointment then) to see if we can possibly hit 128 so I have enough to evenly do a tournament that big. If we don't, I'll have to go with a 96-player tournament unless we're close enough I feel OK with giving some players byes unless subs want to jump into things.
For those asking about it, I hadn't thought about that when I initially proposed this tournament, but considering the whole point of it is a complete ban on the Fairy type to see what the XY OU metagame is like without it, it only makes sense if all Fairy-type moves are also banned. I have updated the OP to reflect this as well.