I suppose there is a fundamental tension here within the idea of 'rights'.
Between autonomy and protection.
That can be a contested issue even among adults (I'm thinking of Operation Spanner).
One note is that this guidance applies both to schools and to some colleges. That's a tricky mix, and really it should be separated out as you're dealing with very young children on one hand and young adults on the other - totally different groups, really.
Damn, I wish I'd noted that in my response. Too bloody late.