[hakfoo]

The problem is that if they offer anything but 1000% bug-compatibility, a Linux-based Windows is just another Windows RT-style penalty box. Yeah, it runs Edge and Office, but none of the closed-source line-of-business software that are baked into people's refined-over-20-years workflow. None of the games with such aggressive and brittle DRM and anti-cheat they break under even official Insider builds. None of the drivers for obscure peripherals that the manufacturer disowned by 2010. You still have a sky-high switching risk.

The way out I could imagine would be some sort of packaged virtualization, like the "XP Mode" feature on Windows 7. Your legacy apps spin up in a thin, well-integrated VM which ran a "final" build of classic Win10 designed for minimal disruption. The VMs, in turn, would be aggressively sandboxed and firewalled to keep it tamed. I'd suspect there'd still be some gaps-- drivers for hardware that can't be easily wired to a VM, but I suspect there's a mountain of logistics and performance issues that don't fit in a two-paragraph post.