Yes, re-thinking it, I wonder if "gender identity" is a bit off-point, because it presumably means whether one identifies as a man, woman, genderqueer, other, or however one either engages with or rejects our societies' gender binary. And obviously preventing people from being discriminated against on the basis that they are not a "man" or a "woman" in the traditional sense is desirable.

But what we additionally want is to prevent people being discriminated against on the basis of being trans or cissexual, ie, on the basis of whether their gender identity aligns with the sex assigned them at birth, rather than on the basis of what their gender identity is, in isolation. If a trans woman is subjected to transphobia without transmisogyny, that means she's being discriminated against not because she identifies as a woman per se, it's because she's trans, ie, the person discriminating against her believes her to be "really" a man but she is and identifies as a woman. So it's kind of meta to "gender identity." Argh. This is difficult to work out.