I mostly agree that the app should only be communicating when exceptional things happen (like failing to save the draft), and my solution of an unnoticeable (but discoverable) status message is meant to give confidence to the users who aren’t very technical and consciously wonder if their work is being saved, which describes much of my target market. The messaging also differentiates these areas from the parts of the app where there’s no concept of a draft and so where auto saving doesn’t happen.