JM - I also believe, as you, about the window sticker. The battery warranty is a new item and probably does not appear on its generic window sticker. Ford has said it will match competitors warranty, so I am expecting they will offer 8yrs/100,000 miles. I have an email into Ford and expect them to respond shortly and will let all of you know.
Marc Lee makes a good a good point about the GM vs Leaf warranty.
So you liked the reverse engineering trick? I can't claim credit for it. It was done by someone on the Ford Truck Entusiast Forum but, I did enjoy seeing my assigned VIN number in a hands on image.