Sure but Thanos isn’t really Guardians villain
If they do Kang he’s going to need to be built and Ant Man is the best film to do it for the reasons I stated
1. Time Travel in the MCU is tied to Pym. Time travel is important for Kang.
2. Kang’s HQ city is heavily implied to be in the comic version of the Quantum Realm.
Kang isn’t tied to a hero like Loki, Doom, Maestro, Osborne, etc. So the film that has the most elements tied to him is the one to use. And it makes sense. Ant Man is an important Avenger and he’s been b tier thus far