the quantum-crypto-cracking threat ... It could be a long shot ... could blow up over-night

The natural behaviour of advances, inventions, inventors, and their champions are well noted throughout history, thus only fools would expect them to be moderated, or used in moderation... when they hit, they slam. Quantum, if it happens, is bound by the same nature. It thus appropriate to develop, compete, deploy, and use some number of privacy enabled PQC coins. As well as PQC versions of other apps. Better safe, or at least prepared to plugin other cryptos, or to go back to the stone ages, than totally sorry.

quantum ... Satoshi's early published public-keys in order to decrypt the private

There are bigger amounts, and potentially weaker keys. Even targeting only missing dead men for key resurrection would need to have solid explanation to avoid killing the network. The first PQC attack whitepaper on anything will kill a lot of networks anyway. Same for AI.

The thought of them getting an enormous cash injection

Even 5% would be too much and hard to squander at once, no, such amounts would be deployed silently for fun and fuckery...