Parts of the memory management code were rewritten for windows 10 to do fun things like randomize the location of the page tables.
This fairly significant change wasn't backported to Windows 7.
Then when they went to backport the meltdown fix to windows 10 they set a 'this page is user accessible' bit in the page tables by accident.
Probably because after Windows 7 they started a kernel rewrite , known as MinWin, to extricate the Win32 Userland tendrils that had crept into the Kernel since the NT days.
The article doesn't seem to indicate that MinWin started after Windows 7. If there has been a fundamental kernel change effort after Win7 (I'm not aware of one), maybe it has a different name?
You're right, for some reason my brain said Vista came after Windows 7. Given that 7 came after Vista my theory makes no sense.