I think the only only scenario where a Nintendo game comes to Xbox is if Xbox collaborates with Nintendo on making a game, maybe Banjo developed by Nintendo EPD (or basically the same devs as the Mario games). I would personally love that to happen cuz for one, Nintendo makes the best platformers and the Mario games are evidence of that, and two, that would be an absolutely historic moment that is two big competitors coming together through a revival of an IP which was popular on one of those platforms in the past but is stuck on the other one right now, and a deal was struck where the game would be developed by one and published by the other, but available on both platforms day 1. Both ecosystems would benefit from it, Xbox would get a very high quality Banjo game and Nintendo would finally get a Banjo game in decades on the goddamn Switch too.
That would be absolutely wild and amazing and never before seen, but I seriously doubt Nintendo is even remotely interested in such a thing even if MS was completely on board with it.