That poster in OP's original GLP link - https://goodlawproject.org/were-suing-virgin-active-over-their-transphobic-rules/ - is nonsensical. It says
"STOP FOLLOWING TRANSPHOBES
FOLLOW THE LAW
Virgin's exclusionary policies are outing trans and non-binary members without their consent"
As if nobody can spot a TiM a mile off in a women's changing room already? They can't seriously imagine they pass. They out themselves. Also, why aren't they proud to be trans, since they identify as trans? None of it makes sense.
And, as a PP said, "non-binary" is meaningless, not only not a protected characteristic in law (because everyone is literally either the male or female sex), but the term has no material definition in the real world, a delusion existing only in the mind of ze/zer/zhem (or whatever the pronouns are).
Anyway, there's little doubt this latest GLP cause will fail, same as nearly every claim they bring. It fills the coffers, however.
I remember Maugham from back in 2016. He used to do the same grift re Brexit. Was going to sue the government, or something. There were multiple crowdfunders. I donated once, so I know how easy it is to be gullible and taken in by him when he's a KC and saying what you want to hear.