"It's just Apple trying to make it easier & more efficient for the NSA to have your documents before you've even finished them."
...and as the big players are threatening the spy agencies with better device encryption, it's obvious that the data has to get to them *before* you save it on your device. So, everybody's happy -- the customer, who *thinks* the data is safely encrypted, and the agency *knowing* that they got a copy of the document before the customer even saved it (all drafts, brainstormings, thoughts, which never make it to the disk included). Brilliant.
Curious to hear what Apple has to say here. It's obviously not a mistake. Saving data and auto-synching it are two different things, which can hardly be an oversight.