Had to look up who that was, but then I found out he's from Yokai Watch, and despite being a staple of Nintendo this decade they don't have a representative in the game yet, so I think you might be well onto something here...
IDK, Yokai Watch was big a few years ago but it's fallen hard. I wouldn't expect to see it pop up in smash, I don't think it's a game series many people actually care about, it was more of a fad.
Japanese Sales (Combined Versions):
Yokai Watch 1 = 1.3m
Yokai Watch 2 = 5.8m
Yokai Watch 3 = 2.25m
Yokai Watch 4 = 0.29m
The series started, peaked and died with the 3DS.