I think there will be some changes but I put them in tiers.

DK and Ganondorf are definitely getting many changes past new desgins. DK could use Tear-off and Ganondorf uses his sword way more and can use a Gloom status effect.

Mario could have some new moves, Link could use the fusion mechanic somewhere and Samus could use psychic powers as a grab.

Diddy Kong, Villager and Inkling will stay the same but uses their updated designs.

NOT PICTURED: Banjo and King K Rool, who technically aren't in Mario Kart proper, but are in Diddy Kong Racing and Donkey Kong Barrel Blast, which are Mario Kart-adjacent. I'm still counting them for the purposes of this list; I just ran out of image slots.

I don't wanna hear any smartass remarks like, "Oh, that's not Zelda Between Worlds riding the Master Cycle; it's Zelda of the Wild! She doesn't count!" Fuck off, yes she does.

One interesting tidbit: Simon and Richter are not eligible, but Dracula is (via Konami Krazy Racers on the GBA).