I think it already is... People are trying to install 7 on new hardware and patching the OS for it to work. There's already SeaBIOS as an EFI module. It is capable of booting legacy OS on EFI "bios". By 2020 there should be other solutions as these so there's still hope for the win7 lovers
Almost half the planet is still using Windows 7, still alive and kicking (today) It'll be interesting come 2020 when a lot of folks refuse lose their beloved 7
2020 might have already arrived. A couple of months ago a member of the Linux Mint forum bought a new Acer laptop, and shortly thereafter he complained that there was no option to enable Legacy/CSM in the BIOS settings. The option to enable/disable Secure Boot was still present, but the machine was strictly UEFI. That will be the final nail in the coffin for replacing Windows 10 with Windows 7 on a brand new machine. Even now, installing Windows 7 on newer machines is difficult to impossible due to the lack of driver support for the latest processors and hardware. And don't ever expect the OEM's to provide them, they would much rather have you buy a new machine. As far as Linux is concerned, the majority of distros already support UEFI, and a handful (Arch, Fedora, openSUSE, Ubuntu, maybe a couple more) already have the digitally signed key that's used with Secure Boot. The rest will either have to get on the train or be left at the station.