Only few miners have concerns of protecting other people's coins locked in P2PK and P2PKH ? This is motivated proposal for fantastical motive.
Miner can no longer act as the custodian for Bitcoin and Blockchain. Every owners have their own concerns for their own coins locked in P2PK and P2PKH. What miners can propose is they can make sugestion to the owners.
Now days we do not need miners to actually verify bitcoin transaction. The bitcoin protocol will do it , itself very soon like the v0.1.
Satoshi can never be so dumb like this. Please, do not mind me, but it is just the truth.
Node verify transactions.
Also this is more than P2PK and P2PKH but about ECDSA/Schnorr signature which would be replaced by Pay-to-Quantum-Resistant-Hash (P2QRH).