As I said elsewhere, I can absolutely believe this article. Also, I can believe it was written by a 14-year old. In terms of language skills my DDs could definitely write like this; they probably couldn't quite achieve the level of awareness of this writer because despite being extremely smart and knowing a lot of factual stuff, they're in some ways still childish in their emotional maturity - I think this is fine BTW, in case anybody takes offence at my description, children mature at different rates.
The Corridor of Righteous Material is something I've personally seen. A couple of years ago at Open Day at our catchment secondary - one whole corridor festooned with the various stripy flags, handmade alphabet-soup posters with all the catchphrases and biologically-incorrect blurb and dodgy stats and kid-friendly cartoons of baked bipeds. It was startling to me, as I hadn't long been corrupted into The Wrong Side of History back then.
(We didn't pick that school, not specifically because of the Corridor I hasten to add).
I can also confirm the sudden explosion of trans identification. This did happen in my DDs' school. Year 7, within the space of a few days/weeks, several girls* declared they were trans and had new names and pronouns (mostly NB apart from one who said they were a boy). The school have gone along with the names, I don't know about the pronouns.
*Girls in the correct meaning of "juvenile human female."