Whereas they can (presumably) see the women belonging to their own group as human, or at least the 'right kind' of women. Men can already make false distinctions about humanity and women's being deserving of it.
I believe that when the distinction between groups will be as large as that between human and non-human it will make it difficult for false distinctions to arise between human beings. Of course, I am also making the assumption that cultural friction that produced the specific case has been reduced through further assimilation to our own societal mores, which is fundamentally what we are discussing.
The porn issue is one where I think an enormous effort needs to be made to teach a simple principle; Fantasy is fine. Willingly fulfilling someones fantasy is fine.* Expecting others to embrace your fantasy is not. The problem is we have relied on this message being implicit in other forms of socialisation, but it probably needs to be expressed as we move into a world that accepts a greater variety of individual expression. It is something that I believe is urgently required, but would serve equally in the case of sex robots.
If a bunch of white Americans bought a bunch of black-skinned cleaning or labour bots programmed to speak to them with 'yes massa' and 'no massa' responses, that wouldn't make you uncomfortable? You don't think African Americans would have a teeny tiny problem with that? It's not real, after all, is it?
It would make me uncomfortable, as I would question the motives of someone who did so until I could be sure whether or not they made the choice through humour I find distasteful or genuine antipathy. I think real African Americans would have an entirely legitimate right to criticise such an action - but if none of the bots was ever seen outside the home, or revealed to visitors or indeed simply never brought to the attention of African Americans I would wonder whether or not it would actually cause harm.
If the harm we imagine causing to people exclusively inside our heads is considered equivalent to real harm, I'm sure we're all monstrosities to one extent or another.