On the other hand, it is not at all unreasonable to expect Dropbox to not sync 0-byte-files (if there was content in it before), which could also lead to the ex

On the other hand, it is not at all unreasonable to expect Dropbox to not sync 0-byte-files (if there was content in it before), which could also lead to the expectation that in those cases Dropbox would store an additional backup/send a message.