I run into this sort of bias all the time -- in the real world, not just in AI. I take my daughter to medical appointments, both for scheduling reasons (my wife's schedule is less flexible) and rapport reasons (I'm not that kind of doctor, but I know the terminology and medical professionals treat me far more as a peer), and I routinely get "oh we expected her mother" or "we always phone the mother to schedule followup appointments".

Is it so hard to understand that men can be parents too?