Well, it's very normal to have quite a few of that many millions of pixels go bad. In DSLR sensors, they can map the hot pixels to black with a firmware update. I am sure if this is a continuing issue with this new sensor design, apple can apply a mapping of hot pixels in their next software update to resolve it. The best you can do is turn them black.
PS - you can get hot pixels when the sensor heats up and that's with low light/long exposure when more power is amplified to the sensor causing hot pixels. When you shoot pictures with adequate amount of light, there is not need to amplify the sensor pixels so you rarely see hot pixels with adequate light shots.
I wouldn't worry too much you have 8million pixels a few or cluster of them going bad is ok but if you see more and more occurring than that's an issue.