Yes, exactly. If you lose it or it's stolen, then you'd want to rotate to a new key quickly. Some of these devices have a pin too, so the attacker needs to crack the pin before they can actually use the device. This should hopefully buy you enough time to bring up a new device and switch over accounts. That's why it's probably a good idea to buy your second device when you buy your first one and store it in a separate, reasonably secure, but more importantly, quickly accessible, location.
