I argue with fascists, exclus, medicalists, and sexists all the time and I’ve never met a sealion. But I have met neurotypical people who expect their sense of cognitive empathy to work on neurodivergent people, and then project all sorts of BS onto them for having a different opinion. IME that term is a dogwhistle for ableism.
EDIT: Just looked up Beehaw’s guidelines and apparently it’s against the guidelines to accuse someone of sealioning so maybe Beehaw isn’t so bad