This messes up some texture packs. See the attached images for a comparison. 1.14.4, the textures face in towards each other, 1.15 pre-release 1, they both face the same direction. This is a downgrade for texturing the Ender Dragon and wasn't breaking any textures having the textures flipped towards each other.
Can confirm this is still the case in 1.16.5 and 1.17-RC1