With a hidden disability, needing to ASK for the accommodation is bad for two reasons:
a) it creates a barrier which does not exist for other unaffected peers (ergo, reducing the efficacy of said accommodation), and
b) it OUTS the disability among the child's peers. That is a BIG no-no when it comes to a hidden disability. If it's medical in nature, our kids have a right to privacy. If it isn't, they still have a right to dignity.
Inclusion isn't just about the letter of the law, but also the spirit of it, which is about making sure that "the children in this classroom/club/activity" means all of "the children." Not just the non-disabled ones.