There's a difference between guiding the general direction of the film cinematic universe and writing the script and jokes to every single movie. Gunn has an approach that has proven successful in both DC and Marvel film universes. He ain't being hired to write every script to every movie just like Kevin Feige doesn't do that.
Agreed, but just like with Feige, these movies are going to be molded to fit his vision. For better or worse, his style from Phase Two forward of just making genre movies with comedy added to distract from the surprisingly high body counts for PG-13 movies works.
While Gunn isn't guaranteed to be doing any writing for the movies under his watch, it's hard to think that as the creative leader, he won't end up pursuing stuff that appeals to his creative approach.
