Again, CPU-Z installs and runs perfectly in my 9879 build once the name of the executable is changed. This tells me quite convincingly that this little hardware reading program is actually just as compatible in Win10TP as it was in 8.1, where it ran fine for years over multiple versions--just as, I might add, your own program did for me--in Win8.x/8.1.
There is no basis in reason or logic for Microsoft to block as incompatible, merely by name of the executable, third party programs it has not tested for such incompatibility. I mean, who thinks "We think it might not be compatible, but we don't really know, so we are going to block it anyway," is an acceptable rationale? Very amateurish & clumsy.
Most people do not buy and run an OS simply to use that OS and nothing else. 95% of the software I've used every day for years (forever, actually) is third-party software not developed by Microsoft. As you note, backwards-compatibility is very important for Microsoft, and they test for it *constantly.* (Even if HG thinks they never do...)
This is a small issue, certainly. But still an important one--I would never have suspected Microsoft of intentionally blocking programs from running in the preview without having tested them--if CPU-Z was actually incompatible with the TP then I would expect it to fail to install and run *regardless* of what its executable is named.