Sexual phenotype and biology are important. And I don't see this person saying we should *ignore* it.

In fact, just the opposite. For medical purposes, my doctor needs to know that I have ovaries, a uterus, a vagina, a cervix, and breasts. My doctor needs to know that I am currently experiencing fluctuations in production of estrogen and progesterone that are lumped together as "perimenopause."

My doctor doesn't need to know what my chromosomes are. I have never had my chromosomes tested. I might have a Y chromosome. We have no idea how many phenotypical females have Y chromosomes because typically we only look to see if somebody is having difficulty conceiving, as having a Y chromosome or, more accurately, the SRY gene, can be a cause of fertility problems. As I'm not trying to have a baby, what my sex chromosomes are don't matter.

I don't see the OP saying to ignore these things. They're saying the opposite, in fact.

They're saying that just because somebody has M on their ID that doesn't mean a doctor should assume automatically, without looking, that they don't have a uterus...which has happened more than once and in at least one occasion with tragic results (he was pregnant and *lost the baby*). Even in medicine, sex is not binary. "Typical" is not universal.

Segregating people by sex for medicine is actually NOT how it should work. It should be about your actual biology.