I noticed that also. One can imagine how many radios are affected. Mine is. One can tell by turning the volume completely down with headphones attached. The squelch is released and the static noise appears. I had the 996t where I was afraid to plug any device into that port because of a fear going around that the main speaker would stop functioning. I am wary to send the 536hp in for anything other than a factory new replacement that does not exhibit the issue. Other than that the radio is of exceptional quality and I am still pleased with it.
I think I understand what you are saying but don't forget it was the factory in Vietnam that was installing the wrong component that got us in this situation. I suppose "Quality Control" will have to be readdressed there as it is common practice to check a certain number of units everyday to catch when something is going wrong. It could be a bad batch of components or the wave solder machine is not working correctly and so on. So, the check of each of these radio pulled for inspection would I think have to be pretty through. Maybe the list of things they were to check did not include the headphone output quality.
Therefore, if Uniden fixes your radio you know it has been fixed and has no other problems because you used it before you sent it off. However, if you want a "Brand New" radio it will have this one issue fixed but may have other problems since it has not been used yet for the other problems to be discovered. This is why sometimes a "refurbished" unit (that has been used and its problem(s) discovered and fixed by Uniden) can be superior to a "Brand New" radio where you get to find it's undiscovered problems (if any) yourself.
I suspect Uniden will be using a combination of new and fixing your radio and returning it to you or someone else to get good radios back into everyone's hands as soon as possible. However, this is a wild guess and only UPMan will know and when he knows he will be telling us.