New Architecture/BIOS chips. They never said that it would work on ALL future intel platforms. Not saying it’s a good move, but just saying they still support Win7 on all systems that were out when it was mainstream.
You're factually correct, but missing the point.
Microsoft said they'd provide security updates for Win7 until 2020. Period. There were no caveats like, "Except if you upgrade your hardware".
Consider this. Apple is a hardware company. They tell you up-front-and center, "Your hardware will stop being supported by our latest and greatest OS releases after some number of years." This is because they want you to buy new hardware after a while.
By contrast, Microsoft is a software company. They could tell you, "Your software will stop being supported after some numbers of years if you get the latest and greatest hardware." That would be okay to do if they let you know up-front.
But no, they pulled it out of their hat AFTER 7+ years. My personal belief is that they are so freaked out by the slower-than-expected uptake of Windows 10 that they are willing to piss off a lot of their base to try to force people to adopt Win10.
This is not policy or strategy. This is strong-arm tactics.