Probably not OP, it might appear once you get the national dex (if more Pokemon DO appear this time again) but it's not in any of the Kalos Pokedex.
Here's a list of Pokemon which are 'missing', Kanpachi compiled it when he completed the game. They're either not available altogether or become available post-E4.
http://pastebin.com/XxfPgw2eHope that helps answer any similar questions you might have.
