You're asking me to provide evidence for the absence of an effect. I'd turn the question around: what is the evidence that encouraging someone to "come to terms with their sex" reliably resolves persistent gender dysphoria?
As far as I'm aware, there isn't a robust body of research demonstrating that it does. By contrast, the existence of adolescents and adults with persistent gender dysphoria is well documented in the literature.
Meanwhile, on the contrary, the existence of adolescents and adults with persistent gender dysphoria is well documented in the literature. That, by itself, is inconsistent with the suggestion that simply "coming to terms with one's sex" is a reliably effective solution for everyone.
Steensma TD et al. (2013). Factors Associated With Desistence and Persistence of Childhood Gender Dysphoria: A Quantitative Follow-Up Study. Journal of the American Academy of Child & Adolescent Psychiatry, 52(6), 582–590.
de Vries ALC et al. (2014). Young Adult Psychological Outcome After Puberty Suppression and Gender Reassignment. Pediatrics, 134(4), 696–704.
Olson KR et al. (2022). Gender Identity 5 Years After Social Transition. Pediatrics, 150(2).