The "school of thought" behind the cultural revolution was twofold:

1) Mao had been frozen out after the disaster of the Great Leap Forward, and this was his way of discrediting his enemies and getting back on top.

2) Young people full of fervor are fucking vicious.

None of it really had much to do with marxist philosophy in general or with the things Mao in particular had said before he'd been frozen out. But it says a lot about power.