User blog comment:KingOfSpriters12/WARNING! CHALLENGERS APPROACHING! - June 10, 2014/@comment-3396321-20140611105038/@comment-5810621-20140611170237

Well, SSBB has 12 newcomers that weren't even unlockable, and another 4 that were bringing the newcomer count to 16. SSB4 only has 9 newcomers, and the roster gets bigger with every Smash game, so its highly likley that the aforementioned 3 characters are within the realm of possibility.