I'm not really sure if or how this is something more easily abused by morally dubious doctors like you describe than various other kinds of treatment which parents could unnecessarily inflict on their children.
And as long as such a doctor doesn't get involved, parents like you describe could still be pretty hellish on their children, that's for sure, but then so can parents who try to force their girl into being more girly, or their boy into being more boyish, than the child wants to be.
Anyhow, for what it's worth, I do think nothing irreversible should be approved until after puberty in any case - but the situation described in the video is kind of a grey area, as the steps taken were in principle reversible but requiring some pretty heavy stuff to reverse. I don't know if you saw the whole video, but at some point it mentions that in order to have the breast-removing surgery in question, Patrick had to go to famously cosmetic-surgery-obsessed South Korea. If your definition of 'reversible' requires surgeries that neither Australia nor the UK will allow, maybe you're stretching it a bit far.