My intuition says that it's very difficult to get a phone to impact glass-first and that 99% of all drops are going to see it dance on the corners, if only for an invisible fraction of a second, before flopping/sliding down on the glass. My intuition also says that those corner impacts are going to be a much greater threat to the hardened glass than the final face-first flop/slide.

The universe doesn't necessarily obey my intuition, of course, but since it differs quite dramatically from yours I thought I'd mention that there's an alternative model of the problem which supports the actions Essential Products is taking.