It is harmful and it is literally asserting genetic superiority? Its not "all people could fly," it is "ancient MALAY people could fly."
While I agree that being able to openly discuss such a topic is wholly fine, asserting it to be true is problematic for a professor who people look towards as beacons of knowledge, for the good and bad that heings. But it is also harmful in that letting crazy theories roam and be treated as just as valid as anything else, is actually a HUGE reason the US is in the state it currently is in. Allowing kisinformation to flow and only pushing back against people pushing back, lets ANY misinformation flow. The giants that still walk among us, the flat earthers, etc, they all exist in a state that is literally dismantling education and sowing seeds for fascism to rise and just generally acting as a direct pipeline to those extremists.