Do you have a citation for "only wants to buy systems which support pure post-quantum cryptography" ?

Because this would seem pretty stupid, i.e. to disqualify something that supports both post-quantum algorithms and previous algorithms.

I have looked just now at CNSA2 and it only says that post-quantum algorithms should be used exclusively for key exchange and digital signatures after 2033.

So during this 7-year transition period it should be normal to use both post-quantum and classic algorithms, even based on what CNSA2 says.

Moreover, even "exclusively" can be interpreted in various ways, i.e. it can also be interpreted that there should be no key exchanges/digital signatures that do not use post-quantum algorithms, but without forbidding them to also use other algorithms, because such a prohibition does not make sense.