I don't want to start a war here, and I don't have the context of what you experienced over there. Perhaps they did go too far. But if you don't know the gender of someone, it is indeed incorrect to assume "he" is OK. That's inclusion 101: don't assume things about people. There is a commonly accepted solution to this problem, used e.g. in the academic peer review world where the reviewer is anonymous, which is to default to "they". That's a good habit to take, costs nothing, and helps (particularly) women feel included. That's a hill I'd happily die on.