They shouldn't be teaching gun safety in schools, because Minors shouldn't even HAVE guns, and if they do they probably already had lessons.
That isn't the point, they carry that knowledge on to when they DO come into contact with guns when they are older, or, the class is taught to middle-schoolers as opposed to elementary.
The main question I have about this is how it's still relevant, I mean do modern adults come into contact with guns enough for this to be useful?
Do you live in the US?