The exact implications of this new policy are still a bit unknown, but according to the snippet below new silicon generations will require the latest Windows platform at that time for support. This means that if you upgrade to Intel's future "Kaby Lake" or AMD's upcoming "Bristol Ridge" you will need to use Windows 10 or you will not be getting full support. You will still be able to install these operating systems on new CPU architectures, but if problems arise you will not be able to get support from Microsoft.
Perhaps more importantly, the post also clarifies that Intel's current-gen Skylake platform is not getting long-term support on older versions of Windows. If you're using Windows 7/8.1, you must upgrade to Windows 10 before July 17, 2017. After that date, Skylake configurations running Windows 7/8.1 will no longer receive support nor non-critical updates. Perhaps this is not a big surprise for Windows 7 as that OS is already on extended support, but for Windows 8.1 it's a bit earlier than expected as that OS had mainstream support until January 9, 2018.
With Windows 7 now in extended support, we are focused on our commitment to deliver security, reliability, and compatibility to our installed base on their current systems. Redesigning Windows 7 subsystems to embrace new generations of silicon would introduce churn into the Windows 7 code base, and would break this commitment. Thus, today we are clarifying our Windows support policy:The new policy is part of Microsoft's push to move the Windows install base to the latest version of the OS. Overall, unless you often call to Microsoft for help this change isn't going to be a big deal for most users.
Windows 7 will continue to be supported for security, reliability, and compatibility through January 14, 2020 on previous generation silicon. Windows 8.1 will receive the same support through January 10, 2023. This includes most of the devices available for purchase today by consumers or enterprises.
Going forward, as new silicon generations are introduced, they will require the latest Windows platform at that time for support. This enables us to focus on deep integration between Windows and the silicon, while maintaining maximum reliability and compatibility with previous generations of platform and silicon. For example, Windows 10 will be the only supported Windows platform on Intel’s upcoming “Kaby Lake” silicon, Qualcomm’s upcoming “8996” silicon, and AMD’s upcoming “Bristol Ridge” silicon.
Through July 17, 2017, Skylake devices on the supported list will also be supported with Windows 7 and 8.1. During the 18-month support period, these systems should be upgraded to Windows 10 to continue receiving support after the period ends. After July 2017, the most critical Windows 7 and Windows 8.1 security updates will be addressed for these configurations, and will be released if the update does not risk the reliability or compatibility of the Windows 7/8.1 platform on other devices.