No it’s not misandry, and I don’t know if ridiculing bald people should qualify as “sexual harassment” per se… but it does kinda feel like making fun of bald people is sort of socially acceptable when it shouldn’t be. It’s something that negatively affects the self image of a lot of men and woman quite badly. I worked with a guy who was going bald and another coworker would frequently give him shit about it, and I could see how it hurt him.
Fwiw I have actually used male pattern baldness as a way to try and explain gender dysphoria to a couple dudes IRL and they actually connected with it.
Edit: I should clarify that I used MPB to help some guys I know empathize with gender dysphoria more than try to explain it, if that makes sense.