The original Mulan was never intended as a story of a woman becoming a man; it was the story of a woman reluctantly taking on a man's identity to keep her sickly father from dying in a war. Not every woman who dresses up as a man in fiction is doing it because she secretly wants a peepee. She could be doing it for convenience' sake because she's traveling through a lawless wilderness and doesn't want to get raped; she could be doing it because she needs a job during an era when women weren't allowed to get them, she could be doing it to serve alongside a boyfriend in the army or priesthood, etc.
If these freaks want to make a movie about a genuine trans woman soldier, they should try researching and portraying one of the many women
who dressed up as men and served during the Civil War. Not all of the women who did it were trans or gay, but some of them could have been. Even so, they wouldn't have bought into the crazy ideologies pushed by Modern Academia and the Alphabet Mafia (but of course, the movie would portray them as having done so.)