It's not about CPU compatibility. It's about Chipset drivers. If Intel and AMD no longer make drivers that work with Windows 7-8.1 then you are forced to use Windows 10.
If you read the article, It's already a PITA to isntall Windows 7 on Skylake via USB (External USB DVD or thumb drive). You have to inject the drivers in a custom image via DISM, first, to get it to work (And yes, I have encountered this with our latest workstations at work)
All it takes is the CPU manufactures to quit making chipset drivers that will work with older OS's, and that's all she wrote.
I'm pretty sure there are no 3rd party chipsets anymore like VIA or OPTI for Intel or AMD, anymore.
The bottom line is that we are at the mercy of the CPU manufacturers for chipset drivers. Whether Kabylake works on current chipsets or not... remains to be seen... but once there are no drivers for future chipsets... that's it.
Get your games from GOG DAMMIT!