I think that confirms that Groot will be back to his good ol' self in no time (to those who watched the original guardians of the galaxy film). so does that mean that groot is staying small just because he wants to?
I don't want to see a Planet Hulk movie. I'd rather see Marvel do a down to earth Hulk movie featuring Rick, Marlo and the return of the Leader. And maybe the introduction of his cousin and his father.