I think this scenario and the reverse scenario will never happen. Nintendo won't buy or be bought out.
For the theoretical, I would like them to go with Microsoft's gaming division. For several reasons. PlayStation is more believable though
Phil Spencer would be a great asset as he currently stands. Argue about the man's PR all you want, but he put effort into improving the Xbox and engaging his team. His approach this gen saved the Xbox from being a commercial failure. Competitive failure is another story, but what could you really do.
Their IP are very different from Nintendo so it would help diversify them.
Halo team's development experience could help Metroid, and even expand it in some ways. Perhaps either other IPs. After the realistic Link tough, keep them far away from LoZ
Rare back where it belongs. I say no more.
