FACT: Diddy Kong has not yet been seen in any gameplay footage for either Donkey Kong Bananza or Mario Kart World.
FACT: Donkey Kong 64 and Diddy Kong Racing have not been put onto Nintendo Classics, being among the very few first-party games for Nintendo 64 that are not on the platform yet.
Those are the ONLY two facts.
One rumor, that repeatedly seems to come up, and just won't die… is that Shigeru Miyamoto dislikes the Donkey Kong Country series and wants to remove elements of it, hence the Donkey Kong redesign and the absence of Diddy Kong. This is a FALSEHOOD. Miyamoto never said such a thing.
It is still POSSIBLE that they are trying to erase Diddy Kong, but I find this to be unlikely. There's a lot working against it. Much of this is opinionated speculation and conjecture, though, so I'm not going to leave it here. I'll leave it in the comments.
by lgosvse