Yes, at work. A man transitioned to living as a woman. She ( I will refer to them as this because this is what was requested, and I am polite, but I remain gender critical) emailed the whole floor to let everyone know that this was happening and that she would be using the female toilets from that time forward.
This was a Local Authority that was known to be 'fully inclusive' and had lots of endorsements from Stonewall as a great place for members of the GLBT (as it was then) community to work. There were rainbow flags all over the place for Pride Day ect, we had lots of gay team members and managers of both sexes, and it did feel like a generally supportive place to work.
But noone asked the women (who were in the vast majority) if this was ok with them, just an email letting everyone know and it was a done deal. There was no opportunity to discuss this decision, and I believe that anyone complaining about it would have recieved short shrift, and would be considered homophobic, as transphobia was not a thing back then. The person complaining would have been sent on an inclusivity training course at the very least, and possibly have been relocated.
I have to say that I do think this person genuinely had body dismorphia, and just wanted to live their life and go about their business as a female. They went on to have top and bottom surgery, and also facial surgery. They were never a problem to anyone as far as I know. But it was the fact that this was what they wanted and so thats what happened, without any consultation with the other women who worked in the building. I don't know if it is relevent, but at the time this was an extremely white workforce, I wonder if there would have been more consideration given to the other women if there were some muslim women in the workforce.
This was actually about 15 years ago, so before the current brand of militant misogeny displayed by the current bunch of trans activists, but the entitilement that this person got exactly what they wanted and blow anyone else's opinion or sense of safety was an indication of what was to come.