Board Thread:Super Smash Bros. Discussion/@comment-20759319-20140503212459/@comment-5773940-20140803201119

I'm pretty sure I read somewhere on this wiki that Mewtwo was scrapped because of the SSE sub-plot. (In my honest opinion, Mewtwo could have easily replaced Lucario in the general plotline, but then again, there was a lot of excitement concerning Lucario. With Lucario in there, the plot would have to be completely re-written to include him. So, in general, he wasn't included because of time concerns, but he just as easily could have been a hidden character such as Wolf.) Please note that he actually had data on SSBB, which supports my rant-post in parentheses. All in all, he does have a fighting chance at being on the new game.

Also, no one mentioned that they missed Meta Knight or MGaW.