They are afraid of Kenneth Zucker's Watchful Waiting model, which proved to be a monumental success. He estimates that around 90% of his underage patients eventually desisted as long as they weren't pushed in any particular direction and given space to develop. The Canadian trans lobby freaked out, going as far as to commit perjury (they said he abused his patients) in order to close the clinic. They succeeded. Zucker was recently awarded $500,000 in damages after it came to light that the allegations were all a sham, but these new "anti-trans conversion therapy" laws means that the only legal way to handle children who show dysphoria is to put them on a path of puberty blockers, cross sex-hormones and surgery. We live in a fucked up world where the idea of a child becoming comfortable in his or her body is legally considered "conversion therapy".