Think About it. It’s tactical marketing. Apple knows that if they release a new color later in the year or six months after the initial release of the latest iPhone, it sparks interest for those who might be contemplating buying a new iPhone, and what not a better way to have a Color that stands out like red. Plus, it has the possibility to help increase sales. Having a Scattered release, I think is still a smart Concept in terms of refreshing the iPhone color.
Also, the Product red iPhone will likely do very well in China, because that color symbolizes good luck as well.