Windows 7 is still under support and it will get patched. They must have patched 8 faster for a reason, but at the same time there are over 10,000 programmers that work on Windows. All split into groups, hell it was 110 programmers just to make the Windows 7 start menu and task bar. And all those groups do nothing but compete with each other, which is why you see so many problems in Windows.
So it is possible that one group simply got it done faster and that the 7 update will be out soon.
Shane