I was a bit taken aback that he posits 'cis women' as the comparator for assessing discrimination, because that implies that cis women do not have a gender identity: in effect, he has made 'has a gender identity' co-terminous with 'has the protected characteristic of gender reassignment' (the concept found in English law).
I can see why, because the claimant is only disadvantaged relative to those of the same legal sex by the 'no manly faces' rule.
A similar judgment could happen in the UK based on the PC of GR, with limited scope for pushback (in cases where fairness, decency or safety is a factor, we can bring in sex discrimination, because women are more disadvantaged by mixed sex spaces than men are: but where's the LAPA in any single sex purely social group?).