But does it matter if we, like the rest of the human race, can’t be totally sure that no aspect of gendered behaviour is innate/hormonal driven?
This isn’t about hormones. Hormones influence behaviour, but people who identify as trans don’t necessarily have different hormone levels to anybody else of the same biological sex. Hormone levels vary within men and women and women with higher testosterone levels are not men.
(Separately, some people have intersex conditions, but that is not the same as being trans. People who have given birth or fathered several children are not intersex)
It matters when you are encouraging people to believe there is something wrong with them if they don’t conform to stereotypes.
It matters if the government is endorsing restrictive gender stereotypes.
It matters because gender stereotypes have oppressed women for so long and now it seems that we are going backwards.