Yes.
But the truth is not that Jack Black believes it (I hope).
The joke is that more than a few hard-core metal heads believe it. That is why it resonated.
I remember the guy and his friend that shot themselves in the head after listening to Ozzie.
One guy lived and sued Ozzie because of the music.
The documentary was crazy. They guy was drooling out of what was left of his face and lower jaw.
I think he suicided by pills a year after the documentary.
Jack Black is an Athiest and attends a synagogue, it’s called a gimmick.