Maybe she's branched out, realized she keeps playing the same thing and decided to try to be different?
Or she just gets spotted too easily as a dude.
I have this theory that the gay Mary Sues, you know, the cockhopping types that act completely like a woman, not a gay man, and have Sue traits; used to only play women but realized they were found out too soon. But then they realized that if they played a gay guy they were untouchable. They could just call you a bigot for calling them out and being gay made them "interesting" (these types usually use gay as a personality trait, not just a sexuality) and therefore not a generic cockhopping Sue.
For a while we were excited to see alternate sexualities in games, but now we're catching on that while there are some interesting gay and bisexual characters, there are also a LOT of attention whores mixed in (just like I've met some interesting bisexual people but a good chunk of them have also just claimed to be bi for the attention, but only ever really dated men.)