I would be OK with some Nintendo IP on XBox/Windows platforms as long as the deal is very favorable to Nintendo.
If Nintendo was making a clear home-only console then it would be a different story, but Switch is different enough from the XBox that they can co-exist.
Also I'd like to see Halo on Switch and Banjo-Kazooie in Smash Brothers and Rare games on Nintendo Virtual Console.
Fuck console wars nonsense, Nintendo isn't even in the console wars anymore really anyway. So who gives a crap about that 3rd grade (my console is better than yours) stuff. Lets collaborate. I'd like to see a Mario game in 4K before 2022, I'd like to be able to play Halo on the go (Switch), I'd like to see Rare games on a Nintendo platform again, maybe not so big of a deal for me, but I imagine there are plenty of kids who'd love Minecraft Amiibo and more Nintendo Minecraft collaborations.
Nintendo/MS are just getting schooled by Sony 3/4 generations anyway, why not work together rather than getting both your asses kicked by the school yard bully as it were.