If a person has had SRS I think it would make sense that their current genitals would survive the change and their hormone treatments could affect their new form as well. Like, they probably wouldn't regrow a penis. But it could go any way an artist wanted. There are no set rules for how lycanthropy works. Even if a person hasn't had hormone treatments or anything the curse might work in such a way that their "true self" would be reflected in their werewolf form, so a trans woman might become a hungry she-wolf!
Back in the 1990s a cartoonist called Rod Kierkegaard had a book out called Shooting Stars, with a story where a character who was obviously Boy George (although he was called something else) became a werewolf. It was drawn in a realistic style and might be of interest to people here, but I read it in a bookstore way back when and it really gave me the creeps. At the time it seemed kind of transphobic and gross, like it was this mean satire about a vain M2F trans person becoming hairy and masculine against her will, but that was a long time ago and I dunno what I'd think if I saw it now. (
Here's a link to see a few pages, if you're curious.)