Oh, there's definitely politicisation going on here, but I don't think it's on the side you're claiming it is. For example, this article says that "Some trans activists have howled at this claim — they believe that desistance is a transphobic myth entirely", linking to
http://www.huffingtonpost.com/brynn-tannehill/the-end-of-the...Now let's have a look at that article:
"For starters, the most cited study (Steensma) which alleges a 84 percent desistance rate, did not actually differentiate between children with consistent, persistent and insistent gender dysphoria, kids who socially transitioned, and kids who just acted more masculine or feminine than their birth sex and culture allowed for. In other words, it treated gender non-conformance the same as gender dysphoria. Worse, the study could not locate 45.3 percent of the children for follow up, and made the assumption that all of them were desisters. Indeed, other studies used to support this also suffered from similar methodological flaws."
Yowch. That's some seriously dodgy science there - almost half the subjects lost to follow-up, assigning a particular outcome to the drop-outs, questionable selection criteria... And the NY Mag completely ignores the actual methodological issues, instead dismissing them as ideological complaining from trans activists.
This is pretty sleazy too: "they just haven’t come up with scientifically convincing explanations for why the studies would all be wrong, and all in the same way". The studies in question took a group of people who met some definition of gender variance and looked at how many transitioned. The more strict the definition they used, the higher the proportion that transitioned - and the NY Mag are arguing that the studies showing the highest proportion of non-transitioners are right and indisputable because all the studies showed some positive proportion of non-transitioners, which is the only thing they could show.