According to the
Model S software/firmware changelog, version 5.9 added the battery preheat feature. (I remember this change.)
So if I got this straight, the new differences are the notification icon in the app, and that it heats the battery even if not plugged in.
I'm not convinced the plugged in part is new either. I've been preheating my car at work for a while, and have on occasion been surprised how much regen was available; as I expected none. Still have to remember to turn range mode off. I turn it on when picking up lunch, because heating the battery then is just a waste.