Not true. Google updated a lot of stuff for AOSP 4.4, such as the e-mail app (which I also thought would never be updated again), the Download app, the Gallery, the photo editor, and a few others. The point is that Ars author's theory hasn't come true yet, and it's actually be contradicted by the KitKat version in many ways.

Look just what a big upgrade the photo editor in the open source gallery received:

http://www.engadget.com/2013/11/03/android-4-4-kitkat-comes-...