All Nintendo needs to do is outsource any of their dormant IPs, and boom another exclusive for the Switch. Nintendo already has developers, and while more is never a bad thing, they don't really need to make that jump. Besides MS and Nintendo have been pretty buddy buddy lately, so I don't see how anything MS does is a direct shot at Nintendo anyway.
And let's not forget that Nintendo reaches some age groups that Sony and Microsoft do not reach with their consoles,that part of the market they have secured with the nature of most their ip's and the image of the Nintendo brand in general.
Funny because well over half of the Switch userbase tends to be over the age of 18, with the vast majority being 19-35. That kind of speaks volumes about who their IPs really appeal to, with kids being in the minority. Just because a game is acceptable for a kid to play =/= mean kids are the main demographic. That kind of thought belongs in another thread that was made recently.
Besides most kids play Fortnite, Minecraft, sports games, or CoD in my experience. All of which, can be played on other devices.