He's already getting offers, WB really wants him. This won't hurt his career, it'll only hurt the Guardians films since he was so much of why those movies worked so well. He'll end up doing more films, probably some DC ones. Gunn has mentioned wanting to do a Metal Men movie.
Now if only he can get past the suits at WB's constant insistence on fucking with the DCEU movies, becuase I've noticed that seems to be where the wheels keep falling off.