The whole point about this is that anyone is what they say they are, at any point.
Any man who says he is a woman is literally a woman at that point, and exactly the same as all other women, and muct be treated as such. If he's a man again tomorrow then that is fine too.
Will this work for women? Not really. If I went into work and said I was a man, I would not immediately be accepted as such by all the men, and treated as such.
And what do insincere people hope to gain?
For women, it might be a way out of the various types of discimination we face.
For men, it opens up access to areas that were previously closed to them.
And the men will still be bigger and stronger than the women, and we are still socialised to be polite and kind, the dynamic is just vastly different.
eg the difference between a TIM who has had no treatment going into a womens prison, and a TIWoman who has had no treatment going into a mens prison. Are the risks / benefits the same?
The inequality - both between the sexes (biology) and between the genders (socialisation) mean that all of this is a terribly uneven playing field. Add into the mix the large minority of men who are sexually predatory and you've got a very unpleasant set-up.