Can it be definitively asserted that deceased children are among the people of Paradise, or does the statement that the child killed by Al-Khidr was among the people of Hellfire because he was a disbeliever prevent that?

A boy who dies before puberty is, by consensus, among the people of Paradise if he is from the children of Muslims. Some have reported a difference of opinion regarding this. As for the children of polytheists, there is disagreement concerning them. The boy killed by Al-Khidr, it was said that he was an adult, and it was also said that he was a boy, and his killing was lawful in the law of Al-Khidr.