Hey Guidio - if you're reading :My thoughts are it is Witchfinder General territory and superstitious to deem a man has transformed into a woman by way of outward appearance. Magical thinking.
This is a male community issue that they should be discussing how to ensure comfort and safety of trans men in their spaces; educating men that they can't become female but they can certainly change their appearance, name etc.
Instead men have thrown the scary issue of 'women's bits' at us and telling us this is what being female is. In particular Owen Jones' insight into women is deemed to be more important than many other voices (bizarrely).
Brains, feelings, thinking, liking, disliking, type,of personality do not mean you are a particular sex. Ovaries and testes and biology get on with that business. A different outward appearance and hormone treatment may be opted for in life, but it does not magically mean you are a female.
This should be a male issue for them to reflect upon, instead they're ducking out and pretending it's transphobia (ridiculous and women aren't being silenced by such attempts at insults).
In fact it's almost going back to the 1970's idea that gay men are effeminate rather than just being men who like men. Just because a man 'feels' female doesn't means he isn't still a man (even after surgery). Men didn't used to feel comfortable with gay men in the changing rooms etc and we've moved on - men need to get over themselves and accept some men are trans and accept them into their changing rooms and ensuring safety.
I'm equally happy with the idea of a third legal definition and spaces if that is the only way to go and a 'heshe' promoun instead of pretending the man has become a she. Heshe is what most people end up saying as it is double speak to try and say the person opposite you is a 'she' when clearly talking to a man.
Either men should step up and be inclusive of trans men or if they can't stomach that debate, then look at the third way. We should not be forced down a hole of doublespeak and thought crime.