The HRT he's undergoing is making his muscle mass higher than cis females, he should be wrestling against other males.
this, sorry..
he's now transitioning into his new physique, which is ultimately different from other female competitors..
I don't think it fair for him to compete against females that aren't undergoing the same changes and would consequently be disadvantaged..
as simple as that...
this is not about bigotry or anything, this is simply accepting his/her wish for the transition and still consider the impact of the change process on the physical level during competition with girls...
Feel free to disagree based on equality principles GAFfers, but if you're aware of male vs female physique differences in general, given the same "quality" of the body of an athlethe, a male body (or male in transition body) will have a clear-cut advantage in most strenght-based sports and that's against competing..
I admit that this sets a problematic situation for this high school student, but at the same time I would rather inconvenience him, than sets an unfair precedent for the whole other competitors..
Not gonna lie to you, this is an ugly choice, but there's no denying the possibility that there will be a clear advantage in physique of the transitioning boy in these matches...