This is one of the main advantages of having a stock Android ROM running on the device as it allows manufacturers to rollout the update almost instantly as long as they get the source code from Google. For those unaware, Android 4.4.3 will introduce an all new dialer app on the smartphone and improve the camera app as well. The customary bug fixes are here as well. It’s an OTA update and shouldn’t exceed 80MB, so you can easily download it over cellular data.
The update might not hit all devices right away, so users are expected to maintain patience if they don’t see an OTA notification immediately.