I saw a post about this on Instagram today from Hemmograms - a pro post. I try to follow people with different opinions to me so I’m not in a echo chamber. Anyway, the point she and others made (other than TW are women) was that it was damaging to women to not allow trans women into women’s toilets because then more masculine looking women risk being challenged.
Not an argument I’d heard before and my brain is getting pretzel shaped to understand it. Trans women are women but need separate permission to be allowed in women’s toilets, which in turn protects actual women being allowed in? But remember, no difference between the two anyway.