Gender 'roles' in the sense you are defining them exist only because gender roles in a more legitimate sociological definition have always existed. We label men and women and become attached to those labels, because we have traditionally expected very different things from them. When we had compulsory conscription and the working women always got fired first, because they always had a fallback role, this really, really mattered. It no longer does.
Since the male role has been extended to everyone now -- women can be soldiers, etc. we no longer have such expectations. So it is not longer really important how we are labeled by the culture.
If it happens to be extremely important to some individuals, there is no longer a pressing public interest in insisting on the label, because it is not the basis for any important public expectations, like going to war, or raising children. It is not clear that this is going to be the case indefinitely, but right now, gender roles mean almost nothing. The expectations of men and women are the same.
Social norms shift. There is not currently a real consensus on what proper gender roles are in our society, so attempts by individuals to press their own chosen definitions of them are out of line with the majority position -- which is that there is not a consensus. When there is not a consensus, choosing to enforce traditional roles because they are traditional is not effecting the will of the majority. It is distorting perception.
In the U.S. at least, when there is no pressing public reason to resist internal promptings, and those are genuine, we defend them. The combination of the 1st amendment and the existence of Pennsylvania means that we have forever agreed to not infringe on religion, and one of those religions, from very early on, has been Quakerism, which has no credal elements and simply acknowledges "leadings of conscience."
There are standards for what the court will take seriously, but for instance vegans do not have to dissect frogs in public schools. This is not a religious idea, but it is seen as an infringement of religion to force someone to violate it. A good part of the LGBT community holds the identification of one's own gender identity to be the same kind of insistence, and a majority of the public in general does not report strongly disagreeing, when actually asked.
History is not an ethical argument, but it has come to have an ethical stance behind it. We have decided to defend quirky individuals when they go well out of their way to hold strongly onto a belief, they are not alone in that belief, and they appear to be genuine in their attachment to it.
Both of the authors you would like answers from the positions of had immense disdain for majority opinions as a way of deciding things. Neither of them approved of majority rule to begin with. Nietzsche considered it a disease of the herd mentality, and Kierkegaard considered democratic opinion the worst form of tyranny.
So the government enforcement of majority norms would disgust them both.
