Part of the reason Kurt Russell felt like a great choice to play Peter Quill’s father was because of Russell’s connection to late 70s-early 80s pop culture, which Hamill certainly has, as well.
If the film was discussed, I’m certainly hoping that a tentative agreement was reached to get Hamill in the movie.
Even if he just voiced some CGI creature, which he has every ability to do, it would be great to get him in the movie.
Guardians of the Galaxy Vol. 2 had its share of major celebrities in small and large roles, and if there’s a similar part available for Mark Hamill, he would be perfect.