I was an employee in Windows on the date of that email. I left a few months later. Note that the email itself doesn't say "windev". It says "Windows" a bunch of times.

If I'm stretching this "windev" thing, the domain for a lot of employee accounts (including mine) was NTDEV, that had a longer history afaik, nobody called an org that..

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.