In other words 'normal people' in his world are people who think like him. Hmm.
People who think like him
this year, if you don't mind ever so.
Back on track - consider first names. I hold it to be uncontroversial and a matter of basic common courtesy to address people by their given name in the form in which we may reasonably know they prefer. So - for instance - Richards may wish to be addressed as Richard and not Rich, Richie, Dick, Dickie or any variant thereof. (Richard Burton being an example here). Davids may well be entirely happy with Dave (or Davey), but may not. It's always best to presume the full given name since you can change it later if the information becomes available.
I don't see why it should be any different with gender. To me it's a common courtesy to interact with somebody on the basis of the gender with which they identify and to address them accordingly. To me it's simple everyday politeness, though I realise and recognise that the mileage of others may vary on such matters.