That's amusing condescension, but of course it's founded only on the fallacies that are rampant in those "postmodern" discourses. Just because you leap to a conclusion and play the guilt-by-association game (in your second paragraph) doesn't mean others have to follow you in thinking so fallaciously.
The distinction between modern and medieval is normative and descriptive. It's just a historical fact that the period of absolute modernity is anomalous in numerous respects. See for example, the expansion of our populations, the decline in global poverty, the increase in the average human life span, and so on. What made those changes possible was the new sort of society, the liberal sort that's modernized/secularized itself. "Medieval," then, can refer neutrally to those societies that haven't caught up. In that respect, most of the Middle East resembles how Europe looked when Europe was still in what we call its early medieval period.
You think poststructural philosophy is going to "problematize" those basic historical facts?
No, the distinction in question is all too relevant, regardless of whether wokesters feel confident they can obfuscate it with pretentious, postmodern gibberish.
In any case, I explain the distinction further here (and see the last link for something on Foucault):
