Wait...what?
You think it's reasonable for YOU to object to getting undressed in the presence of "cis men" but that other women who object to getting undressed in the presence of trans women are hostile and exclusionary?
The difference between a trans woman and a cis man is something that only you and a few other people believe in!
Are we suddenly supposed to respect your right not to get changed in the presence of cis men male colleagues when you've been relentlessly disregarding other women's right not to get changed in the presence of, er, male colleagues?
The hypocrisy is off the scale.
For what it's worth, I don't think "cis men" are likely to be any more interested in using the gender neutral option than "cis women" are. But even if they did want to, calling it, "Women only (trans inclusive)" isn't going to stop them, because all they would have to do is say, "I am trans". The same way literally any man today can say, "I am trans" and use women's changing rooms, which is why we want them to be for female users only and not male users who say the magic words "I am a woman". Because literally anyone can say those words.