T-Mobile has announced the Android 9.0 Pie update for its Galaxy S9 and S9+ models. The Galaxy S9's update is 1964.25MB and is version G960USQU3CSAB, while Galaxy S9+ owners should be on the lookout for an update that's 1988.79MB and is version G965USQU3CSAB.
These updates bring with them Samsung's new One UI. This updated user interface aims to make big screens easier to use by putting the content you interact with in the lower part of the display and keeping the stuff you'll be viewing in the upper portion. Another major feature of the update is a system-wide night mode, which could help to save some battery on those Super AMOLED screens.
T-Mobile is also including RCS Universal Profile 1.0 support in these updates. This means that, when chatting with another person with RCS, you GS9 and GS9+ owners will see typing and read indicators, you'll be able to have much larger group chats, and you'll be able to send larger files.
These updates are now rolling out over the air, so keep an eye out for 'em in the coming days!
UPDATE: Bad news, Galaxy S9 and S9+ owners. T-Mobile says that it's put these updates on hold and that they'll resume "at a later date." We do know that the updates will include Band 28 roaming support whenever they do begin rolling out again, whenever that is. Stay tuned and we'll get you more info as it's available.