[Update: U.S. Unlocked] Samsung Galaxy S9/S9+ receiving One UI (Android Pie)

Update 3 (2/18/19): Last but not least, the U.S. unlocked Samsung Galaxy S9/S9+ is getting the Android 9 Pie update with One UI, according to multiple users on Reddit. The reason the U.S. unlocked model is last is that Samsung needs to test compatibility with all 4 major U.S. carriers to ensure network stability for the unlocked model.

Update 2 (2/11/19): Finally, T-Mobile is rolling out the One UI (Android Pie) update to the Galaxy S9 and Galaxy S9+. All four major US carriers have rolled it out now.

Update 1 (2/1/19): Galaxy S9 and Galaxy S9+ owners on AT&T are now reporting the update as well. Some users have forced the update by changing the date on their phone to February 2nd.

For a while, Samsung was bashed repeatedly for their TouchWiz user interface. Many people complained that it was bloated due to all of the features the company packed into the OEM ROM. It is true that their ROM is full of features, but the core of the issue was its sluggish feel. The company overhauled it with the Samsung Experience update and at SDC 2018 the company announced another change – One UI. We’ve talked about this update at length here across many of their devices, but now we’re seeing reports that the stable version is rolling out to Galaxy S9 and Galaxy S9+ owners on Sprint and Verizon Wireless.

Samsung Galaxy S9 XDA Forum

Smartphone sizes have grown bigger and bigger over the years and it’s caused them to become difficult to use with one hand. Some companies have moved the top tab UI to the bottom as a row of buttons. This has helped, but it’s still been difficult to use some applications with one hand. This is especially true as smartphones have shifted from the standard aspect ratio of 16:9 to somewhere around an 18.5:9 aspect ratio (like the Galaxy Note 9 has). This has made smartphones less wide and easier to hold in one hand, but it has stretched the display and pushed the top UI elements even higher.

Samsung Galaxy S9+ XDA Forum

This is the issue Samsung has worked on with One UI and they have been doing beta tests across a number of their devices as of late. Yesterday, XDA Junior Member zachkirke informed the XDA community that their Galaxy S9+ received the stable Android 9 Pie update (with One UI) from Verizon Wireless. Then today, XDA Senior Member edlee announced their Sprint variant of the Galaxy S9+ also received the stable version of the update as well. While both of these were for the S9+ from these two carriers, we’re expecting it to happen with the regular Galaxy S9 as well.

Refference - xdadevelopers.com