On a slightly different topic, but still ApplePay related....
I was surprised with iOS 11 that when I restored my previous phone to my new iPhone X, it knew all of my cards that I had in ApplePay on my other phone and re-set them up in ApplePay on the new phone just by entering the CVV # for confirmation.
I thought Apple had said that they don't store the actual credit card number on our phones after the initial set up. That was part of the security pitch. If this is true, then how was my account information backed up so that I could restore cards with just the CVV # ?
I think that when I've done previous restores, I had to completely rescan every card to reload it into ApplePay. The watch was the same once I re-paired it with my new phone. Was this an iOS 11 update? How does Apple store this info?