I like nudemac's theory that they were already itching to get rid of him and the recent kerfuffle was just a convenient excuse. I wonder what it was, or if it was just being too political on his social media
Gunn announced GOTG3 and a date before Disney said they were even going to do it. Obviously they were going to anyway, but I think they may have intended on shifting to a new and cheaper director like they did with Thor, etc. and maybe not even targeting 2020 with the new one.
It's not unreasonable to think when a large media company, the same company actually, drops someone within like 24 hours of tweets like Gunn or Roseanne, it was more of a "opportunity, don't miss it" type dismissal. Especially considering how often they're willing to give time or "investigate" until people forget about other instances.
The political thing seems like weird, there's tons of people tweeting like that and his bosses have the same political views and actually I'm just saying "tweeting like that" because I don't even know that JamesGunn was a huge #resistance leader on Twitter, I've never seen anyone repost his sick burns that clearly had to be stopped maybe I should just look instead of continuing to write out this incredibly long run-on sentence.