Have there been any major lawsuits decided?
They're likely to be settled instead of going to a jury.
https://afn.net/legal-courts/2024/06/07/nc-judge-s-ruling-allows-another-detransitioner-lawsuit-to-proceed/
https://nationalpost.com/news/canada/michelle-zacchigna-ontario-detransitioner-sues-doctors
https://unherd.com/newsroom/detransitioner-files-lawsuit-against-gender-affirming-clinicians/
https://spectator.org/it-finally-happened-a-detransitioner-is-suing-the-american-academy-of-pediatrics/
https://www.ipi.org/ipi_issues/detail/here-come-the-gender-detransitioner-lawsuits
Here's the study from April that exposed that patients who had a history of "gender-affirmation surgery" had a 12 times greater risk of suicide attempts:
https://www.cureus.com/articles/201512-risk-of-suicide-and-self-harm-following-gender-affirmation-surgery#!/