Sure, that’s when you have a working and bootable backup. If you don’t (for example because you are using Time Machine) it’s not really clear what you do. I th

Sure, that’s when you have a working and bootable backup. If you don’t (for example because you are using Time Machine) it’s not really clear what you do. I think Apple has thought of some solution, we just don’t know it yet. It’s an interesting question.