Well, other than precedent. We have never seen Intel suddenly surprise the market by using a different core type in a chip family's Xeon SKUs than was used in the mobile and desktop SKUs. And part of that (I conjecture, having been in the rodeo with them since 486 days) is that they like to use the consumer versions of the chips to suss out errata to be fixed before the Xeons are taped out and released. It is true that some features do differ, such as support for ECC RAM and perhaps activation of TSX or extra FMA unit, but these are really just variations on the same core family.