When has Intel ever sold processors that were all homogenous? They have always created many tiers of products that appeal to different customer segments and price sensitivities.

This allows for upgrades without having to replace the hardware. Consider you buy consumer gear at consumer prices without ECC functionality. Then you decide you'd like to run ZFS or something where ECC is encouraged. Instead of having to replace the processor, you just upgrade the microcode.

I had in mind a scenario in which a cloud provider would have access to everything but would be disabling things and selling those nodes cheaper (or, rather, sell nodes with extra features for more), while maintaining a uniform fleet of nodes.