I'm really surprised of not seeing Bandanna Dee here yet... unless I missed a post here somewhere. Nevertheless. I keep feeling he's as much in place of a missing "fourth" as Captain Toad and Dixie are.
Kamek I've also been surprised not being explored in Smash in much capacity (aside from generic stage NPC in Mushroom Kingdom U) - I could argue he could have deployed something like zoning/stage control capabilities based on using various Mario-enemies and/or his Magikoopa spells to influence the terrain with possible lifted elements from Mario-level hazards... Though maybe Plant now fills that niche, so he's been robbed much interesting to add in his own if considered in the future.
On that note, no Cranky Kong yet so far, despite how much fun it'd be to observe him taking arcade libraries of Nintendo in the 80s similar to Pac-Man, but with
more highly self-aware, cynically driven sarcasm?
Wish I could say it's criminal to see these guys missing, but alas, Smash's view on that is easy fodder for tongue-in-cheek mockery, especially with how most of fans, including us are all subjectively biased on that end, which has gone on being never-ending fuel for the recurring civil wars during speculation in more vocal platforms. So I don't see much point on thinking or perceiving characters as "missing" from the roster anymore - the roster we have right now might be outdoing anything a mere collection of notable first parties and handful of 3rd parties by light-year margin, and there's so much to choose for everyone regardless.
Probably it's why I'm merely expecting next Smash-game will only keep pushing similar sentiment of choosing recurring "interesting" picks over what we consider missing All-Stars by likely margin - and even argue today that the concept of "Nintendo All-Star" feels at best one of those "fan mindsets" that only serves to be basis for utter disappointment and anger on the fan when it doesn't seem to match their perception with reality of things. It feels to me that Smash Ballot has more and more become the only best shot where fans' voices based on "missing" All-Stars got heard, hence how it let doors be opened for exploring what we'd consider mainly these fan-favorites from Nintendo's history, with long-rallying support legacies and fame that contrasted more plentiful picks in Ultimate that leaned more on promotional/relatively modern picks in Nintendo's side later on.
And this is before 3rd Parties that are their own can of worms...
Well then, that got quite rambly on my end.