Honestly race is a social construct formed initially out of ethnicity in a very similar way to gender being a social construct formed initially out of sex. I don’t think most people would be offended by someone whose cultural behavior matched that of a race not normally associated with their ethnicity, as long as it was genuine and not done simply to appropriate another culture.

Like, if a white kid is raised around a lot of Jamaican immigrants, falls in love with reggae, and becomes a Canadian reggae sensation, we aren’t gonna say that he’s black (because he isn’t), but we also aren’t gonna say that Snow is appropriating Jamaican culture.

I guess it could be an interesting question for a more open future society, whether “trans-racial” identity could eventually be something we could identify and accept.

But of course TERFy bitch J.K. Rowling isn’t asking this question in good faith, she’s trying to be edgy and punch down, like she’s constantly doing these days. So, no J.K. Rowling. Fuck off.