Metroid is widely (and fondly) remembered for it's atmosphere, exploration, sense of isolation. Not sure if Platinum Games can really get into such a project, especially up to the expectations of the hardcore fans. They are mostly known for their high-intensity, high-volume, and over-the-top action. They can work well with making games like Star Fox Zero (which is why they are co-developing with Miyamoto and Co.). However, it would be an interesting challenge for them if they want to get into something more subtle and slower pace type of games.