I would say if the teeth contain some forensic evidence of systemic egg or sperm production you could at least get male/female. That's as far as it goes.
In other words, hormonal sex as I describe in the post above. There are a few clever ways of trying to guess at this, actually. For instance, if someone has given birth, they must have been hormonally female at birth as far as we know, and experience of pregnancy and birth often leaves quite a few clues on the skeleton. You may laugh - students often do - but this is often a means by which remains are sexed if no cranium is extant and pubic anatomy is otherwise indeterminate.
What is this new and shiny redefinition to support a belief system? "Hormonal sex"?
Seriously, are you trying to say that if a male takes testosterone suppressants and exogenous estrogen, they're also "hormonally female"? What the fuck is that even supposed to imply and why would it EVER matter?
We have all explained several times the impact of hormones and the fine structures of the brain on behavior. These are in fact the
only aspects of morphological differentiation that do, when considering the things "around" sex.
So IF you want to exclude "men" from women's bathrooms because "men behave badly towards women", this might hint at the reason why.
Thus, people who don't produce sperms and do have all the physiological pressures on their behavior of "Emily Lake" may still have penises.
So unless Emily Lake thinks that if someone waved some magic wand and she woke up with a penis tomorrow, and thinks that this would magically mean she would want to start using it to rape women in bathrooms, we can fairly well discern that her complaints can be addressed through hormone modifications and the re.oval of the ability to ejaculate sperms rather than through blanket banning everyone who was born with a penis.
Either way, Emily is wrong to believe this because penises don't "think" for people, their brains do their thinking and that thinking is impacted by hormonal action and the exact fine structure of the brain.