That is exactly what they are doing. Since the Windows 10 free upgrade happened and the sale of the Surface, it was the first time you could get an OS directly from Microsoft. It cut out the OEM and the normal OEM support. In the standard desktop space, OEM was king and retail was a very small number. But now with Windows 10, Microsoft is directly responsible for support. With this as their market aim, they would have no reason to want to support legacy OSes. All of their moves in the past few years are indications that they want to take a bigger chunk out of the OEM market. I also think that the CPU limitation doesn't have anything to do with the OEM or Retail channels, I bet that comes from the Enterprise channel instead.