Here is the Bardfinn post in question:

"There are no (0) physicians offering surgical therapies for minors" https://old.reddit.com/r/AgainstHateSubreddits/comments/izsn5o/transphobia_in_the_comments_of_a_raverageredditor/g73b9de/

Bardfinn is 100% a fucking liar:

Radical mastectomies ("top surgery") for healthy 13 yr old girls in Los Angeles

https://www.youtube.com/watch?v=2TrNE8a53dI

How old does one have to be to consent to a mastectomy? Only 13, it appears. An article in JAMA Pediatrics on “Chest Dysphoria in Transmasculine Minors and Young Adults” at a US clinic was based on a survey which included 2 girls (transmale) who were 13 years old and had both breasts removed and 5 who were only 14. ... However, it’s unclear whether the girls (transmales) had enough time for a mature evaluation of their life-changing decision. For nearly all the 68 participants in the survey, only two years had passed. To affirm that there were “very low rates of regret” among minors seems a bit premature. For instance, a study of women who had a single or double mastectomy found that they were quite unrealistic about life after surgery. “Patients generally thought mastectomy would be worse than it was, and they thought reconstruction would be better than it was,” said the lead author.

13-year-olds given mastectomies at California clinic by Michael Cook | 15 Sep 2018

https://www.bioedge.org/bioethics/13-year-olds-given-mastectomies-at-california-clinic/12816