Yes. Because sex discrimination and sexism are not the same thing. And not all forms of discrimination are wrong. We just use “discrimination is wrong” as a useful first-pass mental hack. But every non-discrimination law is written with certain reasonable exceptions built into it. It is sex discrimination, but not sexism, to refuse to hire cis men as wet nurses. It is disability discrimination, but not illegal discrimination, to refuse to hire someone in a wheelchair to be a circus acrobat.

This is sex discrimination, but it is neither illegal or sexism. It’s not saying that men are inherently inferior to women. It’s saying that there is a bona fide reason to make this space woman-only, based on the lived experience of men vs women.