It just said that where single sex spaces already exist, sex means sex.

There’s no practical way to identify an individual’s sex at a glance. Which creates de facto exclusion for people who present a gender contrary (or simply ambigiously) relative to their born sex.

If you look like a dude and you walk into a women’s restroom, you’re not going to be given the benefit of the doubt.

Gender neutral spaces should be what we’re pushing for

Broadly speaking. But it is a higher bar, precisely because the same misogynists and reactionaries who advocate for anti-Transgender activism and policy are regularly known for serial harassment of straight cis-people whenever the opportunity presents itself.

The problem is rooted in patriarchy and ethno-social supremacist attitudes. Transgenderism is a scapegoat for the abuses of people in power who abuse their authority at every opportunity.