The Moto E was just introduced this morning and Motorola of course has made an advertisement for it. Around the 39 second mark of the ad, when Motorola says that Moto E buyers will get a guaranteed upgrade to the next version of Android, that’s when it confirms Android 4.4.3 is in the works.
Android 4.4.3 has been rumored for awhile now to bring bug fixes to various devices running KitKat. We’ve seen leaks on the Play Store and other places, but now it has appeared in an ad. There still isn’t a timeframe for when it is going to be released, but Google I/O is next month, so it might appear around then.
Source: Moto E Advertisement