https://www.gamespot.com/articles/microsoft-still-willing-to-let-banjo-appear-in-sup/1100-6457595/

One of the most fun aspects surrounding any Smash Bros. release is speculating which new characters will appear in the series, and that has only flared up again with the recent announcement of Super Smash Bros. for Switch. However, fans aren't the only ones hoping their favorite characters make it into the fighter; many other game companies would also like to see their mascots added to the roster. And you can count Microsoft among the companies that would let such a crossover happen with one of its characters.

On Twitter, one fan asked Xbox boss Phil Spencer if Microsoft would still be willing to allow Banjo and Kazooie--the eponymous stars of Rare's beloved platforming series--to appear in the upcoming Super Smash Bros. game. Spencer answered with only a single word: "Yep."