Good faith questions should always be welcome, even encouraged. It would be a sad world where I was still in the dark unable to ask questions about things I didn't know for fear of offending. Thank you my rainbow friends since college. No topic was ever taboo once I started with, "Okay I have one of those questions..."

Reply was always, let's hear it!

Unfortunately, the whole scenario is a little contrived, and it feels quite a bit like the same tactic as describing things like fingernails or the "heartbeat" of a fetus...it's designed to get you to act on emotion without learning more.

Now, if a surgeon were to be found doing gender reassignment surgery on minors without the years of therapy and other interventions that are all part of the real process...then I'd be fully on board with yanking their license to practice and probably charging them and the kids guardians with any applicable criminal charges. As far as the real process goes, the whole thing is designed to give the person every opportunity to change their mind or only partially transition before anything irreversible happens. It usually starts with letting the kid pick their own clothes/hair/whatever and therapy. If they change their mind, they just change their clothes and hair. Then, more therapy and maybr change their name ( it doesn't even have to be a legal change yet, as they're a minor), maybe puberty blockers as appropriate. If they change their mind, they just stop the blockers or go back to their old name... whatever they feel comfortable with. Then maybe top surgery as a late teen or early 20s... again, it's harder to reverse but still doable.

Because of the way the process is gradual and guided by medical professionals, actual cases of someone fully transitioning then changing their mind is less than 1%. Gender affirming surgery to make you look more like your ideal version of your assigned sex (breast augmentation/lip implants/whatever) have mich higher regret rates.

Unlike what some people may have told you children aren't allowed surgery, and are rarely allowed hrt. Sometimes they get puberty blockers, which is somewhat controversial, but is also used in cis children with precocious puberty. It's been demonstrated that even small children have formed a gender identity (can't remember the exact age but it's around 5 or 6 years old), and that this doesn't really change. It is possible for someone to not know their gender identity, though I think this is more common with non-binary people and those who aren't taught about gender identity.

What do trans people think about the possibility of a child or preteen “getting it wrong”? Ie, maturing into an adult that realizes/decides that they actually want to live out their life as initially assigned at birth?

i'm not trans, but i think there is always the possibility of being wrong, and the only real thing we have to back this up going forward is long term heuristics.

Notably if you've been cross dressing for a couple of years, chance are, it's gonna be pretty fucking low that you would regret it. By that point at least.

Maybe one day we will develop some kind of technology that gives us a better way of classifying this, in a more reliable manner, because theoretically there should be some form of expected brain adaptation from the average person, or related physical issue in the case of physically intersex people.

Ultimately, having a more positive opinion on less binary genders in general is going to be like 80% of what solves this problem. The second that non binary and genderfluid is more universally accepted, the trans existence is probably going to shift more towards the center. Simply due to social acceptance. Though i'm sure a lot of people will still ultimately be trans, i'm just curious to see how this plays out.

That's my two cents on it at least.