Got it ..because Bitcoin security is NOT a bandaid type anti virus .. it is built into signature scheme .. like the network itself is a Security software 😎😎

You're conflating chain splits with backwards compatibility.

The simple question from a layman is : what happens to Satoshi's coins ?

If something like my migration BIP activates then either Satoshi upgrades the locking scripts for their coins or they get frozen. While my research suggests it should be possible to enable a recovery option for BIP32 wallets, there's no additional data available that JBOK wallets would be able to use to prove to the network that they aren't a quantum attacker.