Well apparently according to the movie coming out next month, a young cisgender gay man.

Why stop there, why not make him bisexual or hey, bicurious. Why not just make this 100% fictional character an ally?! Ally to Hero, the new slogan for Stonewall.
Well this is the kicker: the real initiators of Stonewall wasn't him. There were two individuals credited with sparking the movement that set LBGT surges all over.

Marsha P. Johnson, a transwoman and drag queen, was the one who started it first and is credited for assisting many queer people at the time.

There is also Sylvia Rivera, a Puerto Rican transgender woman, also pivotal in the movement.
They are not cisgender gay men. This is a huge example of bastardizing movements against discrimination, much like how they portray Rosa Parks as "a tired elderly woman" when she was actually a huge contender in civil rights long before the bus ride.
The director's claim that they're including all identities is a load of bull crap, especially when the main character is white and cis.
note: Any comments about the image/looks of the two women I posted are banned. Keep that **** out of this topic, this is about the 2015 movie and its whitewashing and transphobic actions.