If the school does not allow gender neutral language, the student should follow. Some may be too young to even understand gender-neutral language. For example, kindergarten in Sweden is too small to even understand pronouns. At such a young age, he does or acts this way due to surrounding influences. It's natural for children to say or do what they believe is right to do, but focusing primarily on a child trying to eliminate all gender bias is quite ironic because at that age they are just starting to do so.