All the Right Moves was the first major lead role for Lea Thompson, meaning she wouldn’t have been in a strong position to bargain with filmmakers regarding the nude scenes.
These days he uses that power mostly to make sure he gets to do his own stunts.
Tom Cruise, as the star of the film, and also something of a bright star on the horizon of Hollywood, while not wielding nearly the power he does today, certainly would have been in a better position to fight the nude scenes.
Of course, what makes this story great is that he didn’t have to do anything to help his co-star, but he apparently felt it was the right thing to do and Lea Thompson tells Closer, that it meant a great deal to her.