Oh, Robert. You’re arguing with the wrong person. I have a degree in Psychology with a concentration in early childhood development. And, I’m a gender advocate. I know my stuff in this niche.
Your statement that the “psychology community generally agrees that gender dysphoria in children usually resolves on its own by the onset of puberty” could not be more wrong and outdated. Actually, the onset of puberty is the negative triggering event for trans youth, the point at which (research shows) they spiral even further downwards into depression and anxiety because their external presentation is shaping up in a way that doesn’t match their internal sense of identity. The onset of puberty in trans kids, especially when combined with an unaccepting family & community, is one of the biggest predictors for being at-risk in attempting and/or completing suicide.
But don’t take my word for it, that trans kids know they are trans, even if they lack the verbal skills to communicate that. Or that the psychology community (and medical, and psychiatric) all agree that affirming trans youth is the best way to go. Try reading up on all the current positional statements from the medical, psychological, and psychiatric professional organizations, who all state that supporting trans youth with affirmative care is the best practice.
Those statements of support can be found here, from the AAP (American Academy of Pediatrics), here, from the American Academy of Nursing, here, from the AMA (American Medical Association), here, from the American Psychiatric Association, here, from the APA (American Psychological Association), here, from the APHA (American Public Health Association), here, from the Endocrine Society, here, from the AACAP (American Academy of Child and Adolescent Psychiatry), and here, from the WMO (World Medical Association).
Those are only a few.
Also, it sounds like your info is vastly out-of-date. I wrote a piece on the basics of gender. You can find it here, titled “CISGENDER?! Is That A Disease?” Or, a primer in gender vocabulary for the curious-minded