We're making assumptions about their genitals based on a complicated mass of social cues.

We're not actually gendering the people around us based on their genitals. And consider that while quite a lot of people will say that one's genitals are the defining element of one's gender, we very rarely see the genitals of the people we quite automatically assign gender to. I know unambiguously masculine cis-men who have more breast tissue than some unambiguously feminine cis-women. Less than a hundred years ago, pink was a 'boy' color.) And cues that we will often talk about as though they're non-negotiable are full of exceptions-breasts, for instance. These can change from culture to culture, or even from decade to decade (just a couple hundred years ago, high heels and hose were a guy thing. Hairstyle, kinds of clothes, even certain colors of clothing. I think it's worth considering (though I know you didn't bring this up explicitly, but I feel it's sort of lurking in the background of your question) how much of what we consider to be 'obvious' about someone's gender when we look at them is actually a set of social cues.

They care about it, maybe, as much as we care about hair color. So, they're humans, and as such come in all sorts of genders, and they know gender exists, but it's not really a thing they care much about. Ann Leckie So, I don't think I've ever said that Radchaai are gender neutral-just that they really don't care about anyone's gender, and don't mark it socially …more So, I don't think I've ever said that Radchaai are gender neutral-just that they really don't care about anyone's gender, and don't mark it socially or linguistically.

Ann leckie books in order