But the tone and context are not a convincing threat as the comment was made as a joking example how "insane" he was instead of a credible threat targeting anyone specifically.

There is a serious question on proportionality here. Kids do and say stupid things. You cannot bar them from their rights while forcing them to attend school to "protect" them, meanwhile throwing the book at them for every minor stupidity or bad division they might undertake.

Lately I hear more cases of ruining lives by charging minors with ridiculous crimes than school violence... Protecting the youth...