Ah. So you are a true believer.
You believe that something in a man's mind can make him actually, meaningfully more like a woman than he is a man.
Which means you believe that the actual difference between men and woman is mental not physical. To you, all the shit that has happened and still happens to female people (the ones with female bodies) often by male people (the ones with male bodies) is nothing to do with a woman.
And you know what? You are actually right. Of course you are. By your definition of woman, all this is true.
But all you did was change what the word means. The shit that has happened and still happens to female people (the ones with female bodies) often by male people (the ones with male bodies) didn't go away. Trans women are still members of the group of people that have male bodies.
So, while I can entirely accept that this group of "womanny minded people of either sex who want to pee togther" exists, and accept that to be accepted as part of that group is important to trans woman for all the reasons you a gave, nevertheless it is incredibly unfair to women (in the other, sex based meaning) and frankly sexist in the extreme to take away all the supports put in place for female people (the ones with female bodies) because you want to give them over to the group of the wommany minded instead.
Because while it may provide dignity, health, safety, privacy and humanity for the wommany minded, it is at the same time forcing all the female people who do not identify as womanny minded, but simply as female people with female bodies, to be lumped in with people with whom they share neither sex nor gender. And that means taking away the dignity, health, safety, privacy and humanity of female people who do not want to be defined as people of womanny mind, nor share their suppoedly single-sex spaces and supports with people with whom they share neither sex nor gender.
Because regardless of how the wommany minded male may perceive himself, in the reality he must share with others he is no different to any other male person : male body, male eyes, male touch, male experiences, male expectations. So in priotising his view of himself and his priorities over those of the female people whose resources you are giving him, whether you intend to or not you are going down the age old path of making women's primary purpose that of service of a man, with their own needs being made second to that.
Now to be clear, I'm not saying this newly reconised group of "womanny minded people who want to pee togther" should not also have their own spaces and pprotecions - god no! All I am highlighting is how utterly unfair it is to achieve that by taking them away from the people they were created for while those people still need them too.