That's actually not true. What is "neo Marxism"? As I understand it, it is the application of Marixist class theory to other non-class power structures. However I have seen nor have been able to find any evidence that this is an actually existing group that has grown out of Marxism. Furthermore, postmodernism denies the very structures in the materialist understanding of history which is essential to Marxism. So how are they compatible? These and other issues are discussed in my post and in the article I linked therein.

There's simply no evidence for it; Peterson's confusion is his own and I hope that others do not follow him on this and instead choose to do their own research into philosophy.