Of course it is.
Which means women need to be ready with the counter move, which is that should the TRAs ever succeed in securing a no-sex-based-carveouts ruling that TW actually are the same as women, we mobilise outside the no-longer-meaningful word "woman" and outside the no longer meaningful concept of "women's rights", for rights based on our sex alone.
Because we then have the argument that since sex is irrelevant to "womanhood", organising our voices to speak about what we face because of our sex, and making the practical and moral arguements for provisions that we therefore need for our sex, to ensure it is not an unfair disadvantage to our freedom and our practical ability to excercise our theoretical human rights, is entirely irrelevant to and separate from trans women's needs as women.
In short, if they ever "win", they also immediately lose because in winning the right to be women despite their male sex, they also create the concept of female sex being something entirely separate from and irrelevant to women including transwomen.