I regularly go to the Ford Sync website to check if there is an update from sync 4.4 to 4.6 for my two 2010 Mercury Milan Hybrid vehicles. Today to my surprise when I checked it came back that my vehicles do not have Sync installed! I called the ford help line and they stated they recently update their website and the database has some problems they are trying to correct. I did verify on the phone call that the 4.6 update is not yet available for my vehicles.
https://owner.ford.com/tools/account/sync-my-ride.html#/home/