Why?
Because it would be trans exclusionary.
Not of the penis-possessors who would be upset at being left out. Of the vagina-owners who are very clear they are not "cis women."
My feminism has room for the female human beings who have been so impacted by the cruel gendering of society that they feel they can't fit into womanhood. My restrooms have room for these individuals to change a tampon or pee without the penis-owners causing them undue risk.
Now, I know that this inclusion may make some people angry, because these are female human beings who do not wish to be included in the category "woman" and yet I am grouping them together. I suppose this makes me a Trans Inclusive Radical Feminist, since I center female human beings. It wouldn't make sense to call me the "E" version unless my focus was on biological males instead, who, after all, only make up one segment of trans people.
I am proud not to exclude my trans brothers and biologically female non-binary siblings from the spaces female human beings fought to use free of the oversight of male human beings. I won't accept a women's room that gives them no refuge.