In a world where latency:storage size tradeoffs need to be made for practical reasons (and will, at some point, be required for fundamental physical reasons), we should just embrace NUMA anyway. Death to the lie of uniform access! NUMA is the future!

Ehrm, anyway.

It actually isn't clear to me whether designing a two socket motherboard is fundamentally an easier task than jamming more of the things into a single package (given that they have already embraced some sort of chiplette paradigm).

They have done this previously for dual socket Xeons. Historical precedence doesn’t necessarily hold here, but in fact, it’s been done on the “cheese graters” previously

The Mac Pro (and the high-end Powermacs that preceded it) were always available in a dual socket incarnation, right up to the trashcan Mac.