What we know about the current state of Guardians of the Galaxy Vol. 3 is that James Gunn had already submitted the first draft of the script to Marvel.
Guardians Vol. 3 was expected to drop in 2020, likely in early May.
Does Disney’s decision to cut ties with Gunn mean that they won’t use the script that’s already been completed?
It’s possible they could start the film from scratch in order to be sure no trace of Gunn is associated with the movie.