CZ suggested when discussing the threat of quantum attacks: The Bitcoin community could consider a quantum upgrade in the future, giving old address holders 6-12 months to move their coins to new quantum-secure addresses. If they don’t migrate (including Satoshi’s coins), those coins would be frozen under the new protocol to prevent hackers from stealing them. This would reduce the BTC supply on the new chain to 20 million. What would Satoshi’s reaction be if one day they opened their wallet and found their coins frozen?