Also the other thing about that JKR Asking a Random Guy About His Opinions on Kink post is that she has totally failed to clarify the core thing about proponents of the "autogynephile" theory:
Even If It Were True What Would That Change
If transness was a predominantly sexual experience - so what? It's no skin off my back. I get a sexual experience in public when I have a really good bagel, that doesnt mean bagels should be illegal.
Fundamentally, none of the stuff trans people ask *me* to do costs me anything. They could be doing it specifically to make JKR mad and it'd be nothing to me.