wouldn't surprise me that much to see him do an uncredited cameo in that movie, just like Matt Damon in Interstellar
That wasn't a cameo, it was an important role and commentary on NASA culture, and a foil to Cooper as well.
Mann (Matt Damon) waa about both how the loneliness of space can drive people insane, but aldo the danger of a common culture at NASA and associated parts, among people like Robert Zubrin, that of always putting the mission first, ahead of people.
I spoke to a friend who works on the engineering of human space fight. He said Damon was one of his favorite parts of the movie, because he is the perfect answer to the questions he gets from ignorant journalists at press conferences on a regular basis.