i think more of a case that they have redefined what spam is. It seems they now produce a serps to mirror their own vision of what sites they want to be returned on the first page. When they started they worked on an algorithm that they let decide what a strong site was. So the serps were the result of the algorithm, now it seems the algorithm is led by the serps. The goal seems to be an algorithm that automates what they would do if they were left to hand edit the serps.