After silver was removed from circulating coins, proofs were still being made out of the current clad composition. In 1975-1976, they made 40% silver bicentennial proofs as well as clad proofs. in 1977 they resumed with the clad proofs that are still being made today. In 1992 they also started making proofs of 90% silver. So I guess the answer to your question would be No! A proof is a proof. Clad proofs are cheaper naturally than the silver proofs. Your
State Quarter proof is still proof, not prooflike, although it's probably impaired.