Okay I could not find any official statement from the NHS, but from what I could find it seems the claim was made from a few detransitioning stories ignoring the millions of happy trans people, and like I said the regret rate is insanely low, the regret rate is somewhere around 0.2% to 2%, and again most of which probably didn't get any medical care for it. especially not children. I feel bad for people who regretted it but using detransition stories to tell people who are actually trans that they shouldn't transition is just dumb, detransitioners can not say what transitioning is like accurately because staying transitioned and being happy with it is the most important part of transitioning. in which a lot of trans people don't regret it and has improved their well being, again refer to the source I provided. and studies show that gender affirming care in trans minors improves their mental health.
https://abcnews.go.com/Health/gender-affirming-care-trans-youth-improves-mental-health/story?id=96510337
so stop using that very few people who regret transitioning as proof that the people who need gender affirming care shouldn't have it.