Of course they are women, which makes it upsetting for them (and me, watching), when they are misgendered (or missexed, if you prefer) AND gaslit here by those who pretend that women can always tell, because some mystical women power.
Do you live in the UK, CatherinaJTV?
I'm in my 40s, have been around a bit, and I've never once seen any woman "misgendered" in front of me, "watching", in any loo, ever. Neither have I ever encountered any woman in person, GNC or not (and I'm LB myself), who's ever told me this has happened to her, either in North America or anywhere in Europe.
I don't doubt it's possible and might occasionally happen. But I am, I have to say, pretty surprised that you can have "watched" this happen multiple times. Is this in Germany? (In my experience in Germany women are less bothered about being "gender conforming" that in the Anglosphere.)
Why, in any case, would GNC women be either surprised or offended by being accidentally "misgendered"? I've never met any adult woman who particularly cares if someone accidentally mistakes her for a man? It really is not something that adults really care about in the main. If GNC women cared desperately about being mistaken for a man occasionally, presumably they would dress more gender conforming, no?
It's like your whole argument is weirdly filtered through a trans sensibility, without any awareness that for the vast majority of adults especially GNC or LBG adults misgendering isn't a thing, and certainly isn't amazingly offensive.
The only straight people who tend to get upset about misgendering are the very gender-conforming types who put football shirts and flowery headbands on teeny babies in case they catch the gay
I've never met a butch lesbian who's having conniptions because someone thought for a moment that she might be a man in the loo. (People who care about that kind of thing usually festoon themselves with gendered items just in case, not the other way around....)