Do iPhone batteries still roll over and die as soon as temperatures drop below -0°C? I recall poor battery performance in the cold was a problem for some iPhone users at work, but this was several years ago. If battery performance hasn't improved, that would make this new feature, well, let's say of limited use.
I have always been disappointed that when flip phones were a thing, none of the ones I knew of made a sound when you opened it. That and a way to customize the opening sound seems like a pretty big opportunity missed. (And I'm not even a Star Trek fan.)