That's what being a female homosexual is.
Indeed, we invented a word for it, because it's a real, semi-common phenomenon.
I do not believe being attracted to a particular gender identity is a thing, as I do not believe anyone (even Layla Moran) can perceive a gender identity. Maybe we could get some paranormal researchers together with some sex researchers to prove that someone can actually respond to a gender identity.
We can perhaps skip the paranormal bit and try to get the sex researchers to figure out if someone can be attracted to a stated gender identity. Check for increased/decreased arousal after hearing someone state their pronouns? Again, doubtful.
(Finally, sure, gender presentation will be a factor, but they're not advocating for that. Demanding any particular presentation is transphobic).
So they're trying to take away a word that describes a real objective phenomenon and apply it to something that no-one has demonstrated exists.