Wouldn't Disney want to completely re-write the script so they don't have to give Gunn credit? They might keep the songs but I feel like they're going to start the script from scratch to avoid any association with Gunn.
If they do, they might have me on the brink of boycotting it.
That said, I doubt they would completely rewrite it. It's just too much work and takes too long when they can just use something that's already finished and is likely good. Plus, many of the GotG cast are showing their support for James Gunn as a director and as a person, I think it'd be disrespectful to them too to have their characters' final chapter be rewritten from nowhere. I do think they will make changes just so they can say it's not Gunn's script, but I doubt they'd do it all from scratch.
I'm also a little unsure on how much Disney really wants to disassociate with him. I think it's obvious they couldn't have possibly hired him without knowing about this, and I find it hard to believe that they took the decision to fire him overnight considering he was probably the second most important person in the MCU after Feige. That, along with Gunn's "I'm okay with it" reaction, makes me think maybe they always had a deal where if the shit he posted in the past was too exposed, he'd get fired, because obviously Disney's PR would have a hard time keeping him... and if that's the case, I'd assume the people at Disney still respect him.
But honestly, whatever. I'm sick of Disney at this point. I thought they were gonna keep their hands off Marvel, but apparently those days are over... I'm expecting them to go full Star Wars soon. Nothing good can last forever, I guess.