Board Thread:General Discussion/@comment-25200461-20141217013133/@comment-25689844-20141217211920

They confirmed he would be paid DLC for Europe so far, so I don't see them not doing it for other areas, especially if it's Europe and not Japan.

Link: http://ca.ign.com/articles/2014/11/20/mewtwo-will-be-available-as-paid-dlc-in-smash-bros-after-all