Worse, it's the total opposite of one core tenet of postmodernism. It's very hard for anybody honest to argue that postmodernism has ametanarrative, when the only thing all authors agree with is that metanarratives are to be recognized and refuted.
> I've read enough post-modernism to form my own opinion.
Who did you read? Deleuze? Derrida? Foucault? Baudrillard?
I will always advise people to read Baudrillard first, I think he is somehow misunderstood in the Anglo world, but it might be mistranslations. Then Deleuze, then Lyotard and Foucault as Derrida is too dispersed imho, and way to complex, as imho you have to read his articles where he explain his books, alongside his books [edit: and to be fair I still don't think I really get Derrida, he's very recognized but to me he is very obscure, probably the weakest imho. I also disagree with a lot I understand from him, except his method, so that's might be my priors who prevents me to really getting it].
If anyone would rather read a novel to try to grasp what postmodernism is about, I think "l'Amour" from begaudeau is the latest (100 pages, really short and sweet), and the one that is still in my mind when I think about postmodern materialism.