Those people are called "cis", because traditionally when an opposite of "trans" is needed "cis" is it.
You know, we don't have a word for people who aren't schizophrenics or say don't believe they are avatars of a god either.
If someone cares strongly about whether they're regarded as male, female, or something else, then in the absence of strong special reasons for doing otherwise we should go along with that preference.
- If, for instance, they take on the considerable social cost of telling everyone that they want to be known by a new name, addressed with non-standard pronouns, etc., that is good evidence that they care strongly.
Except we don't, and can't, apply that logic in any other situation, otherwise we'd find ourselves going out of our way to accommodate every ...
Like I said in the parent. I'm not taking orders from a glorified janitor in the middle of an emotional meltdown.
Except "cisgender" boys don't generally engage in questioning "am I really a boy".