I don't see anything to support this in the literature. The overwhelming majority (94-98%) of youth who transition maintain their gender identity many years later as adults. [1][2] It's hard to imagine they would continue treatment if it was making them miserable.
[1] https://www.pbs.org/newshour/nation/transgender-kids-tend-to...
[2] https://www.thelancet.com/journals/lanchi/article/PIIS2352-4...