No one knows what causes gender dysphoria. Is it biological? Is it psychological? Is it nature? Is it nurture? or is it the result of interplay between several elements?

Because we do not know what causes it, it is only rational to consider all possibilities; and I don't read anything more than this in the article.

I know you are concerned about stigma; but the potential for stigma is not sufficient reason to dismiss reasonable possible causes.

These questions, however, are secondary. What we know about gender dysphoria, scientifically, is (a) it exists; (b) it causes significant, unrelenting suffering and a huge spike in suicidality; (c) except for a handful of outliers, there is no cure; and (d) there is only one therapy with any consistency of positive effect: transitioning.

And then the dirty little secret: some people's lives vastly improve when this course of therapy is followed -- which suggests that it is not a mental illness, though it is not conclusive.

There is no reason not to pursue this course of therapy, regardless of the cause of the condition. At the same time this therapy is being followed, the possible causes can be investigated separately.