There is a whole other issue about fungibility as well. Should we still allow hackers access to those Bitcoin, or condemn governments for attempting to censor it? This would be like Ethereum V Ethereum Classic again and hopefully we won't have to reach that stage.
Good point, i could see that happening in the future. As for censorship, it's already happening on centralized service and i expect only minority Bitcoiner condemn censorship towards stolen Bitcoin from vulnerable address.
Change address is quite commonly used now
People are now more aware about coin controlling and coins privacy than before. I do it always but never had this Quantum Computing awareness before when using change address.
Or they simply use wallet which do those by default. It's shown by people asking why their wallet keep generate new address or send Bitcoin to address they don't recognize (in reality, it's just change address).