This is really not all that different to kids realising they are gay. If, say, 5% of adults are gay, then it follows that about 5% of kids will grow up to be gay. Some will realise at an early age and some will not. Of those who do realise, some will come out early and some will not.
But we're not just talking about 'coming out' as Trans.
We're talking about Socially Transitioning children who think they might be trans.
Social Transitioning is not a neutral act. It can be immensely hard to row back from if they decide they aren't trans after all.
Percentages of children who think they might be trans has rocketed, far, far in advance of your 0.5%. This most heightened in certain groups; autistic girls, children in care, gay children, children who've been sexually abused.
So should teachers, totally unqualified in this area, be putting these children on path that we know can be detrimental? Or should we be giving these children counselling and support to understand what's driving their perceptions of themselves?