AT&T nor any other carrier ever promise a specific date for a phone update. The reason for this is because certain bugs may pop up during internal testing which would require the carrier to send feedback to the manufacturer and then the manufacturer would have to make a completely new build which addresses the bugs found during the testing.
It's a matter of its ready when it's ready I'm afraid.
It does not appear that the original poster ask for a specific date . He asked for a time frame . IE :early spring , mid summer ect . . The plans for release in Korea were annonced almost a month before the release , whitch went OTA on the 27th of march .
The 4.4.2 kitkat update will ruin your G Flex's gaming performance. On 4.2.2 gaming was flawless and smooth. I was getting over 36000 gaming score in antutu benchmark app. It was showing high frame rates and was very smooth. After the auto update to kitkat 4.4.2 gaming performance decreased drastically. Games that ran smooth now ran slower. I re-ran the antutu benchmark app. My score went down to 28000. Antutu showed that my CPU and GPU were no longer working that hard. My G Flex was faster than a Note 3 and S5. After 4.4.2 it is now slower. There is some sort of CPU limiting to save battery now that can't be turned off. That is why the 4.4.2 kitkat update mentions battery performance increase. Others I have spoken too that have got ton 4.4.2 on their device are also upset. It appears the samsung S5 & Note 3 running on 4.4.2 from t-mobile does not get this issue. The G Flex for some reason does not like 4.4.2.
I was lucky I was in my return period and exchanged my G Flex out for a 4.2.2 and gaming is bliss again! No issues. How do I turn off or disable the 4.4.2 kitkat update from returning. I simply don't want it my device is running fast and smooth. I ask that att run antutu test on a G Flex on 4.2.2 and then afterwards on 4.4.2 and you will be shocked to see how much slower the G Flex is afterwards. I am very upset that I can't find a way to turn auto updates off. Again, I am very happy with att and my G Flex just the way it is.
Here is the link to antutu. It is a legal test app in the google play market. Att needs to see good the score was on 4.2.2 beating other devices and carriers. The score was in 36000 as many of G Flex reviews will show on YouTube. Now once updated to 4.4.2 the G Flex's CPU / GPU performance is severely decreased. The moving yellow ball test moves choppy at slow frame rates. On Quadrant with 4.22 the G Flex was in the 22000's. After 4.4.2 installed that went down to 18000. 4.4.2 kitkat is running the G Flex in full time battery saving. And yes, I did reset my phone afterwards and no change in performance except erasing everything. Now I have a replacement phone on 4.2.2 and wish to keep it that way. Please tell me how. And please try this test. thank you.