many hilarious things on this thread, but this especially-
they might identify as non binary specifically because they feel that "woman" is heavily linked to a bunch of social roles/history/narratives that they don't identify with but are fine with the biological stuff.
allow me to introduce a revolutionary new concept, feminism, which amongst other beliefs proposes that 'a bunch of social roles/history/narratives' are part of the system in place to OPPRESS women- and are not inherent in being female whatsoever. Therefore women are entirely at liberty to refuse any or all of these 'narratives' (aka stereotypes) and will still remain women.
Thanks to 2nd wave feminism, there are thousands upon thousands of us who have rejected stereotypes, are perfectly content with our biology and have grasped the astonishing fact that we can chose how to be women without calling ourselves something different.
hence myself and most of my contemporaries have amazingly navigated pregnancy, birth, breatfeeding and beyond with short hair! and trousers! and without make up!
amazing, but true