if someone at that university tells you the self you are dealing with is a fiction you are not going to be pleased with her are you? What about students with strong religious faiths that influence every part of their being? Should Richard Dawkins be sacked were he still employed for professing his atheism loudly and writing 'The God Delusion' ? I am a gender atheist, that puts me on the same level in that respect as him.
Biological sex is binary, and that's a fact. There are two gametes and two gametes only. Nobody has ever found a third, fourth or more. Just because there are anomalies does not in any way disprove that. Humans are bipedal, some people are born with less than two legs, that doesn't mean there is a scale of how many legs humans should have, it means something went wrong. Differences of sexual development, DSDs, do not mean there aren't two sexes. Every single human that has ever been born was the result of a gamete from a male, the sperm, fusing with the gamete of a female, the ova. We were all born from women, even surrogate babies are born from the uterus of a woman, the body that doesn't have a penis.