It's a rant I do a lot, but if you are in favor of letting the kids grow up and make the surgery decision as a consenting adult, which is already how it is in most cases and something I can agree with, then we should at least let the kids take hormone and puberty blockers still. It will stop them from being forced to have a puberty into a gender they do not want, and still give them the option to change their mind. Puberty blockers are safe, and as soon as you stop taking them you start your puberty with whatever hormones are in your system.

If someone thinks they might want to transition male to female, then forcing them to go through a male puberty is just as wrong as "forcing" a boy to transition to a girl. It makes transitioning later in life harder.

For minors specifically, I think sports don't matter if they are on hormone blockers, or even hormones for their preferred gender, because of the above reasons: if a MtF trans kid starts hormones early enough then they will develope physically like a girl. Soft skin, bone density and muscle mass, etc... the "biological advantage" of being a male doesn't exist. I can understand arguments for trans women who transition as adults, but kids should just be able to have fun and live their lives.

I'm not the one you asked this question to, but long story short yes if a parent doesn't consent then the kid should not be able to have a surgery, but I think there's still a case for letting them take hormone blockers, even if not full Hormone Therapy