This could be:

Great for security - Being able to safely compute secrets is a very difficult problem.

Fucking awful for security - More OEM secret controls and "analytics" that devolve into backdoors after someone yet again post keys online.

The platform owner can manage keys and data contracts in the processor, that should enable them to rotate secrets constantly.

In other hardware there is an OEM secret because the manufacturer is trying to keep users out of "their hardware", in this case we're trying to keep everyone except the data owner out.