Interesting. Apple hasn't updated how the wallpaper settings work to match the actual lock screen. At least not for the 12.9" iPad Pro. I'm not sure how the smaller iPads look.
Until Apple fixes the problem, all we can do is manually adjust the location of the most important feature of our new wallpaper. If you are playing music or audiobooks in the background, they appear on the right side of the lock screen, instead of the centre as before. If you have any current notifications, they appear under the off-center clock.BTW, this is the same on my iPad Pro, iPad 4, and iPad Air 2 which are all on iOS 10.