I thought PQC systems were wrapping classical encryption within the PQC protection so even if you broke PQC you'd still be left having to crack classical. Of course some hypothetical future QC could then accomplish this task so the future proofing goal of PQC would be violated.
The proposal is to do exactly this (hybrid schemes using a pre and a post quantum scheme).
However in this context the debate is just over the PQ scheme (not the overall system). Also, NSA are not planning to mandate a hybrid system for government use. Others may do the same.
