If you watch the video, one black of sapphire is going to make at most 500 iPhone screens. Probably less. Apple would need 1000 machines to meet production needs. Probably more. The current plant has only 60 machines. So very unlikely for iPhone screens. What would completely lose performance or easily scratch? Camera lenses. Touch ID sensors. A watch crystal that could bang into walls.
Samsung's mobile division now makes more profit pet quarter than Google in its entirety. See the last chart in this article:
Their profits are within a factor of two of Apple.