Not out of the ordinary in showbiz. Same thing happens in modeling events, sports events and heck, many have blacklisted North Carolina because they refuse to integrate bathrooms into one size fits all.
True. My Mom was a manager of a Frederick’s of Hollywood for years in San Diego. She was asked to help put on a fashion show once and asked me if I wanted to work with her on it. Of course I said yes (I was in high school), even after she told me I would be working in and around the dressing rooms where there would be naked models. Sadly, it did not happen. She got some girls to work it instead.
So I've been told. It's a semi-private space, not a private dressing room, and definitely not unisex.
At one point in my life, I was going up to NYC for my employer, to supervise photo shoots, involving lingerie. Good female lingerie models are very expensive. The first trip up, I was startled at how nonchalant the models were about just stripping down right then and there, to get into the next item or items for the photographer. I mentioned it, and was asked if I wanted to pay them $200 an hour to walk off the set, change and walk back. Said they'd be happy to make more money, but most didn't want the added expense. So, they continued undressing and dressing on the set.
Same thing happens backstage on Broadway. It's been that way since forever. You get used to it.
Heck, the entire cast of Hair came out naked on stage for the finale. Dianne Keaton was the only cast member who refused to do the final number in the buff; she gave up a $50 bonus every night by refusing.