I think it's time for Nintendo to invest in new development teams

[PAOerfulone]

I don't think hey need to purchase new dev teams as much as they need to expand the ones they already have.
Namely, I think Game Freak could use quite the expansion for Pokemon Switch - which will be the first mainline, HD, console (or console-quality) game in the franchise and a huge leap from the 3DS.
I also think they can expand Retro Studios so that it doesn't take them 4-5 years to make 1 game like it's taking them now. Alongside working on Donkey Kong or whatever Nintendo franchise they're tasked with, they can make their own new IP as well, a more Western-oriented one at that.