According to the memo, "each platform release will have a 'GMS approval window' that typically closes nine months after the next Android platform release is publicly available." Considering that GMS stands for Google Mobile Services and covers apps like Google Now, Google Maps and the Google Play Store, a manufacturer is going to be damn sure that it follows the request on the memo.
Android 4.4 was designed to work with devices using 512MB of RAM or higher, allowing low to mid-range models to use the OS build. With this in mind, Google does not see the need for outdated versions of Android to be powering a new phone. Considering that we are past the halfway point of February, the policy certainly should be in effect now.
If you're interested in reading an intelligent look at the fragmentation issue, check out this report written back in December by our own Michael H.
source: KnowYourMobile, MobileBloom via Pocketlint