Single post in Sprite Discovery Discussion

After following along this discussion over the past week, I wonder if this has been considered. In the past, I have seen sites whom update sprites provide the option to the user to remain using the old sprite or update to the new version. Of course, newly hatched would automatically be using the new sprite. This also adds another layer of value to retired sprites and essentially to the game as well, as those sprites can only be obtained through user-user trades.