Prior to the release of Guardians of the Galaxy Vol. 2 fans were spreading all sorts of crazy rumors about Nathan Fillion’s cameo in the movie. It turns out, he’s not really in the movie at all. His cameo was cut, and it was only in the form of fake movie posters in a scene that didn’t make the final cut.
James Gunn explained on Facebook:
“I didn’t have a good cameo for him in Vol. 2 – and I wanted to bring him more fully into the MCU at some point, so I didn’t want to make him Aakon Guard #2, narrowing his chance of a more substantial role in the future. I really do love the character of Simon Williams/Wonder Man in the comics – a sometimes douchey actor/superhero – and could see Nathan clearly in that role (not because he’s a douchebag but because he’s great at playing one). But, of course, in a movie set 99.9% in space I didn’t really have a place for him. So in a small flash to earth I decided to put a theater playing a “Simon Williams Film Festival,” with six Simon Williams movie posters outside. Obviously, from the posters, he’s had a run of B movies. Most of them in themselves are Easter eggs of some sort or another. Unfortunately, the small section of the scene where they appeared slowed down the movie and I had to cut the Easter eggs from the film (along with storefronts named after comic book luminaries Starlin, Mantlos, Annett and others). Equally a bummer was that a lot of people took photos of these posters on the day so suddenly every fan site was reporting that Nathan was playing Wonder Man in he movie. He was even the third-billed actor on IMDB!
So that’s the full story. Nathan’s only cameo in the movie ever were these posters. I’ll post them all over the next few days.
And, yes, I think we can consider them canon for the MCU, and I hold onto hope that Simon Williams will rise again!!”
So yes, he would’ve been Simon Williams/Wonder Man…if his Easter Egg cameo had made it into the movie.