I don't believe the roster picture "leaks" are real, those look fabricated. BUT... I'm starting to believe that some of the characters it has (Shulk, Dr. Mario, even DHD) may actually show up on the final roster, that the person who made the roster picture heard from another source who was playable.To be fair it is a pretty good leak. Im starting to believe it myself.
Either way, this bodes very well for Mewtwo in the long run, and brings back a sense of excitement I haven't felt since before Greninja's reveal. I don't dislike Greninja, but after his inclusion was when the doubt was planted into everyone with the excessive "Pokemon cannot overrep Mario" comments.