That's not what I said, I said a character who didn't feature in a title of theirs since pre-Brawl, which is different than making a cameo or small appearance.
Of which K. Rool, Isaac, and Takamaru (and most retro characters) can all fit. As well as any "historical reps", if that's really a thing.
In the past we've received characters who hadn't appeared since the previous gen (Samus, Ness, Marth), who had only made relatively small appearances in the years prior to their inclusion (Diddy Kong, ROB, G&W), and who hadn't appeared in any capacity for a long time (Ice Climbers, Pit), and this time we didn't get any of that, we only got characters who were relatively front-and-center in relatively notable games post-Brawl. You're saying you wouldn't want to know if that was a coincidence or most likely done deliberately?