In a command prompt, use winver. Note the version listed
EG, Windows 95, NT 4, 98, and ME are all considered Windows 4.x.
NT 4 and Windows 95/98 don't use the same kernel at all. They might share the GUI sub-system (actually, it's called the Win32 sub-system, which is probably what Windows Team blog is referring when referring to API versions, since Win32 is the Windows API) (and yes, I know the 64 bit version is called Win64, just like the 16 bit version was called Win16), but they do not share the same architecture/kernel at all, which Smitty inferred. So no, Smitty wasn't right at all, is use of the word kernel was wrong and confusing.
Anyway, the only way it makes sense again is Windows NT releases. I doubt the Windows Team Blog are in on marketing meetings.