How long before WCCF tech pick this up?
Actually this is old news. I remember a discussion back in 2014 talking about it.
Since W7 the OS runs tests on the underlying hardware to see which hardware is best used for timekeeping. Then makes a decision based on the hardware it found if it will use TSC or HPET or ACPI PM. If TSC is not compatibles with the hardware, uses HPET and if that is not found uses ACPI PM. However HPET & ACPI PM have serious overhead tax on the IPC, hence they are the backup generators.
If somehow MS has some bug in the code where on Ryzen is using HPET or ACPI PM because it cannot see the CPU as TSC compatible one, could be the case of the perf differences.
I remember back then, many reported huge improvements on the FX8350 (8320, even 1090T) by disabling HPET in Windows 7 and 8.
But this is too technical and everyone jumped on the bandwagon "FX8350 sucks".