You are correct, but we're talking about asymmetric key crypto in general, not just encryption. Presumably the GP is referring to quantum-resistant hash-based signature schemes such as https://en.wikipedia.org/wiki/Merkle_signature_scheme

I am not claiming that you can though.

Then you probably meant to start a new thread. The one you are replying to is about encryption exclusively.

I think that was in reference to public key cryptography, not in reference to hashing, but I'll leave it to the OP to clarify, that's at least how I interpreted it.