Earlier quoted context omitted.
I am pretty sure there are smart locks that don't rely on an active connection to the cloud. The lock downloads keys when it has a connection and a smartphone can download keys. This means they work even if no active internet connection at the time the person tries to open. If the connection was dead the entire time between creating the new key and the person trying to use the lock it still wouldn't work. If there ar…
It may not be worth the complexity to give users the choice. If I were to issue keys to guests this way I would want my revocations to be immediately effective no matter what. Guest keys requiring a working network is a fine trade-off.
If the cloud is down, revocations aren't going to happen instantly anyway. (Although you might be able to hack up a local WiFi or Bluetooth fallback.)