Someone changing their gender is not a sexual activity. There was nothing salacious about david927's comment. If anything it is an interesting sociological data point, given the small number of prominent women in math and science.
Sexual reassignment surgery is not a sexual activity, but it is part of someone's medical history, and I think it is in poor taste to gossip about someone's medical history. If Ms. Fridrich had been hospitalized for depression as a teenager, would that also be suitable for discussing on HN?
