James Gunn's role in the MCU has been overblown by fans, according to Marvel Studios head Kevin Feige.
There’s no discounting the fact that Gunn infused the “Guardians of the Galaxy” movies with his unique style and managed to create a sort of “Star Wars” inspired enterprise for the 21st century. With the Guardians success, the MCU quickly adopted Gunn’s brand of humor and action into their other movies as a result.
In other words, GOTG and its characters were the future of the MCU and the direction it was going to take, with Gunn leading the way. Hell, at some point, Feige was hinting that “Guardians of the Galaxy Vol. 3” would be the central nucleus of the MCU’s upcoming fourth phase, post-Avengers. Does Feige remember when Gunn stated in 2017 that he was "shepherding the future of the Marvel cosmic universe"?
And thus, firing Gunn, because of past tweets, must have completely scrambled the proceedings for Feige and Disney. He was supposed to be the visionary that led the way. However, in an interview with CinemaBlend, Feige tries to downplay Gunn’s role and states that we all got carried away in thinking he was the maestro conducting the ship of the MCU:
"His influence was Guardians. It was Guardians. It was his input on Guardians and the Avengers films, as you've seen in Infinity War, and on the Guardians 3 script, which we’re still using. So you'll see that influence. I think online, sort of the notion of ‘architect across multiple cosmic things’ was slightly blown out of proportion."
Yeah, sure … Ok, Kevin.