Well I checked my Windows 95 VM, even opening a command prompt and typing "date"; changing the date view in that panel does change the date instantly. I never knew this was the behavior.

He describes changing the behavior in Windows 2000 being "reluctant"; I would say it was the proper and expected design from the onset. Windows 95 does not have instant-change settings anywhere else, it's always safeguarded behind OK and Apply buttons. Changing the date immediately on changing the view is inconsistent with the rest of the operating system's GUI design.

Yup, absolutely. I'd go so far as to say that in a window with clearly labeled OK/Cancel/Apply buttons, the instant change is a straight-up bug.