Gattis has been let go. It's done.
That said, it's not because Mario doesn't believe in that style of offense. It's more because Gattis is a poor play caller, poor recruiter, and generally just a goofball that Mario got catfished on. Mario is going to make a hire that runs a similar offense because Mario is confident that he can build an OL capable of running that style of offense. He doesn't believe he needs to resort to gimmicks in order to build the trenches, and he has good reason to be confident. Just chill the f*** out guys. It's done.