Previously, setting a live wallpaper (not a static one) would simply apply it everywhere. Android 7.0 included the option to choose the location for static images, and 7.1.2 extends that to live wallpapers as well. This works on built-in wallpapers as well as those installed from the Play Store. So, you can have a live wallpaper on the home screen while leaving a static pic on the lock screen.
This update has been tested on Beta and on 7.1.1, and it’s only showing up in the new build. We can’t rule out that this is related to something else like Play Services, though. From the image above, you can see that you can apply a wallpaper either on Home Screen or on both Home and Lock Screen.