I think a new Banjo game would need to be as good as something like Astrobot to even get the interest of people outside the few 100k Banjo fans who really want a new game.
But it's more likely that MS wouldn't achieve that so that sales would be pretty "low".
I still think they should work on it but I understand that there's not much to expect from. But it sounds like a good Gamepass and Switch 2 game to me.
Release it on Xbox, Steam and Switch 2