You know this makes me think of something completely tangential. If you get a gender-reassignment, are you then no longer gay, but simply straight? If you are a homosexual man, and you feel like you are a woman trapped in a man's body, and you get surgery to turn yourself into a woman, you are no longer a gay man, but rather a woman, so you are a heterosexual then, right?
https://en.wikipedia.org/wiki/Gender_binary