For those of you, who didn’t know:
If you don’t free up your “Cloud Capacity”, which is the case if you don’t delete the autosaves on disconnect for one hour, you get an extra feature:
An error will be thrown to the GUI in the multiplayer loading scream, if someone alt-f4 or crashes back to desktop. So you don’t have to guess, if someone dropped or has an old computer.
Of course the error message is only thrown, if your cloud is full. Because it says, that it can’t save the file on disconnect.