Honestly, I don´t think the other 2 characters will be Ex versions of existing characters.
It is possible, but besides Iori I think the rest of the DLC will be new (to this game).
I also have my doubts about this whole "Classic Iori is broken" chit chat. I am pretty sure he will kick ass, but being broken?? I really don´t think so. We'll just have to wait and see I guess.