I wonder how Dixie and Diddy would work as a duo if Dixie hadn’t been scrapped. Maybe a DK barrel that acts as an “extra life” because you need to KO both of them.
Also I remember that “Breath of the Wild” Zelda was considered for Ultimate but replaced with her “Link Between Worlds” version because “BOTW” Zelda was more about research and study rather than combat. Then two years after Ultimate’s release, “Hyrule Warriors: Age of Calamity” was released, where Zelda from that era DID fight using a Shiekah Slate (and later gaining her powers).