My understanding of it is that each firmware is tied to carrier / region and when you install to your phone (ie debranding) you now have tied the phone to that region. So when that region gets a release it'll be available to your phone. You can of course continue to manually install the firmware of choice as they become available or you can restore your phone to current carrier / region firmware if they have received the update faster.
Currently I have the latest R2BA020 (a carrier from Germany i think) firmware on my phone and have noticed that the apps available to me have now changed. Certain paid for apps do not seem to be available now. Again its only my understanding of things and my reasoning from having a debranded cell.
Hope this has not clouded things further for you
"People not things effect change."
Steve needs to learn this, ditch the iPhone for an open world.
Android - Linux for the people.
The Techno Mage
Moto D PRO | HTC DhD | NOOK COLOR cm7bt