No, it just means that changes to privacy that affect existing data should be announced beforehand. However, I doubt that they'll tell you which data will be affected.
Have fun scrolling through your entire FB history to update permissions!
Not really. If they provide clear and transparent notice to users on what they are doing with their data, then what they are doing is fine -- "caveat emptor."
Face-palm. That's an oxymoron by definition.