The journalist writes it though, as do many other folks.

I didn't come up with this definition myself.

If I am not mistaken, I can probably even dig some Sinosfky references using it.

I think it was sort of externally derived based on "DevDiv", but as another former MS employee - albeit from DevDiv - I can confirm that "WinDev" is not something that was routinely used inside the company the way "DevDiv" is. Usually it's just "Windows", or "Windows org" if the context is ambiguous.