The script of Guardians of the Galaxy Vol. 3 was not changed by the story to Avengers: Endgame, according to James Gunn.
James Gunn recently discussed Guardians of the Galaxy Vol. 3 through his Instagram stories. Fans were curious about whether or not the big changes in that movie affected where he’d be taking the movie, since (spoiler alert) the Gamora that we meet at the end of the movie is from another universe and Thor has seemingly joined the team. James Gunn’s response was that he was aware of these adjustments prior to his temporary dismissal from Marvel Studios, and they were already accounted for in his script.
You can read James Gunn’s comments directly below:
“The script will change because my scripts always keep changing up until the moment I shoot them. But it won’t change according to anything from [Avengers: Endgame], because I already knew what was in that script before I wrote [Guardians of the Galaxy Vol. 3].”
That doesn’t quite answer the question of whether or not Thor will be part of the Guardians of the Galaxy team in their third movie, but it seems that the character’s ending in Avengers: Endgame will be directly addressed within Guardians of the Galaxy Vol. 3 itself.
Here is the official synopsis for Avengers: Endgame:
The grave course of events set in motion by Thanos that wiped out half the universe and fractured the Avengers ranks compels the remaining Avengers to take one final stand in Marvel Studios’ grand conclusion to twenty-two films, Avengers: Endgame.
Directed by Anthony and Joe Russo, Avengers: Endgame stars Robert Downey Jr., Chris Evans, Mark Ruffalo, Chris Hemsworth, Scarlett Johansson, Jeremy Renner, Don Cheadle, Paul Rudd, Brie Larson, Karen Gillan, Danai Gurira, Benedict Wong, Jon Favreau, Bradley Cooper, Gwyneth Paltrow, and Josh Brolin.
Avengers: Endgame is now available on Digital HD, 4K Ultra HD, Blu-Ray, DVD, and Disney+. Meanwhile, James Gunn’s Guardians of the Galaxy Vol. 3 is in development at Marvel Studios.