You think parents should get their kindergartens an Apple Watch?
Perhaps you think I'm referring to children past elementary school.
Regardless of what Apple says AirTags are and are not for people will use them however they see fit. For example, they are not for tracking pets but there are pet collars designed to hold an AirTag so clearly many people are ignoring Apple.
Attaching an AirTag to a child's backpack seems like an obvious way to track one's child, even if it's not supported use case.
The purpose isn't track things you know how to find but to find things that get lost; like children. There is also enough paranoia about kidnapping that I'm sure there are at least a few children in every classroom that are tagged.