But apparently the CPU and chipset work well enough to run enough of the operating system that windows update can display a GUI error message with error code "Code 80240037", which is what the OP link to.

Who would design a chipset that is backwards compatible enough to boot windows and all its services in GUI mode, but not backwards compatible enough to run windows update?

If you run an old Linux or bsd kernel on these chips, do you get to login to X only to find a kernel error when you run apt-get update?

But the drivers aren't part of the OS nor are they written by microsoft. I don't see why Microsoft would block the OS running on a particular generation of CPU.

If they know the vendor won't write them, it could be argued that they're just stopping the users from making a mistake.

The vendor does write them, at least in some instances. Gigabyte has explicitely announced support for Windows 7 on their new AMD Ryzen boards.

Reference: http://www.gigabyte.com/Motherboard/GA-AX370-Gaming-5-rev-10...

An old Linux or BSD kernel will work just fine on these new chips.