one thing I don’t like about most post-WWII French philosophy

Somehow, they all think that referring to someone else’s argument as “classical” automatically means to strike a devastating blow.

No, it doesn’t. There are both original and blandly academic ways of getting back to the classical roots of a problem. Leibniz, for instance was extremely “classical” by the standards of his century, far more so than Spinoza, but Leibniz was every bit as original as Spinoza, even if he remains a bit less popular at the moment.

The way to be avant garde is to oppose academicism, not to oppose classicism. The two things are not the same. This is true also in painting. Cézanne’s admiration for Poussin is a case in point. The novel is not the same as the original.