Going back to Sardine's example upthread of all women shortlists - I always think the Warchowskis are the perfect example of why moving to "gender" rather than sex makes a mockery of the whole idea.
They made probably the most influential sci fi film of that decade (I personally have always thought it was a bit over-rated, but there's no disputing the fact that it was of enormous importance). Thing is, they pitched, got the funding, cast, directed, marketed the whole trilogy while presenting as the men they were born and brought up as. Is there a chance in hell that two women would have managed this? Not on your nelly.
So too AWS. It's very telling that one of the possible beneficiaries of the rule change is someone who's already had one bite at the cherry as a man (and is lying about age and previous experience).
I think it's very important to be able to say "why is this measure in place? Safety? Privacy? Bodily autonomy? Redressing an imbalance? If it's redressing an imbalance, what sort of imbalance - the lack of women due to sex discrimination, or the lack of trans people due to genuine transphobia?"