But it seems fairly clear about if a space/service has been provided for women, separately to men, then it was a needed single sex space for privacy, decency and all the rest of it.
Sadly the converse is definitely not true, certainly historically. Single-sex spaces for men were the default. Then there was sometimes a supposedly equivalent – but not really – space for "the ladies, bless 'em".
I'm just being a bit careful about this because I really don't want to inadvertently make it easier to recreate spaces from which women are banned from for spurious reasons. Especially decision-making spaces.
To quote an AS Byatt character from memory: "All the important decisions were made in the pub, to which I was not invited." Sums up the situation of my younger days all too well.