I'm a broken record with this, but Smash needs more DK series reps now. K.Rool and Dixie are the first 2 obvious choices, but you've also got Cranky, Funky, other enemies....etc. We need somebody.
At this point, Zelda needs another rep too. Sorry, but Fire Emblem having the same amount of characters as Legend of Zelda is crazy to me in terms of widespread franchise appeal. Skull Kid are Impa both make sense, are long established and popular characters, could have interesting movesets, etc.
Metroid deserves a third rep (cue Ridley. No really, I'm a delusional Ridley supporter for life).
Idk maybe this is weird, but I kind of feel like they should save Inklings for the next game? They may want to capitalize on Splatoon's popularity ASAP, and of course the next Smash game is probably 5+ years in the future, but I feel like if there's GOING to be another Smash game they have to save SOME big guns for it.
I feel like there needs to be a female DLC character before it's all said and done for sure.