Samsung Galaxy S9 and Note9 devices got recently updated to Android 9.0 Pie and now the second phase is about to start including the S8 and Note8 flagships. Both of these devices are currently on beta testing for One UI and a new announcement revealed that the Stable version of Android Pie is about land.
According to an update notice, Samsung will close the One UI beta program for US Unlocked Galaxy S8, S8+ and Note 8 phones on 12 March 21:00 EST (9 PM). After the end of this program, there will be no more beta updates and beta feedback and community will be deactivated.
At the end of this update Users of both of these phones will receive a stable software release that could possibly be added as a patch and will not weigh as a full build. Also, the users on Android 8.0 Oreo may receive this OS update in the same week
As this happens, it's expected that the carrier locked S8 and Note 8 will also get the Android Pie update very soon.