Does this mean DX7 & 8 stuff is detined to no longer run
Course not. That would mean everything older than about six or seven years old would not work any more on any operating system.DirectX SDK isn't the same as DirectX runtimes (which is what Average Joe will have installed).
They should have gone the same way they did with NT4, bare minimum of support for the old tech and streamline and pack in new features and methods.
What, and have everybody crying foul because "Micro$oft are forcing - yes - FORCING me to upgrade!"?