Apple Wallpaper gone in recent versions of iOS? Has Apple been replacing their Wallpaper images during updates of iOS 7, 8, and 9?

My iPhone 5s has an image of a blue-green aurora borealis that I assume was Apple-provided. I don't recall installing from outside. But now I do not see that image listed in Settings > Wallpaper > Choose a New Wallpaper > Apple Wallpaper in iOS 9.2.
Yes. Nearly every iOS update phases out some of the wallpapers and introduces new ones. They typically phase out the oldest wallpapers while adding new ones into the mix. Many of the earlier iOS versions introduced and phased out fewer images, but the last few have introduced more, and subsequently removed more. 

The dynamic wallpapers have stayed the same since they were introduced in iOS 7.