> [...] including transitioning blockchains to post-quantum cryptography (PQC), which is resistant to quantum attacks.
PQC is not defined as "being resistant to quantum attacks" nor does it necessarily have this property: PQC is just cryptography for which no quantum attack is known yet (for example even when no one has tried to design a quantum computation to break the cryptography). One can not demonstrate that a specific PQC altorithm is resistant to quantum attacks, it is merely presumed until proven otherwise.
I think that "having no known quantum attack" is a reasonable interpretation of "quantum resistant". If there were no possible "quantum attack" (under appropriate complexity assumptions, such as EC-DLP not being in P), then we could call it "quantum proof" instead of quantum resistant.