Samsung's surprise release of the final Android Pie update for the Galaxy S9 and Galaxy S9+ wasn't followed by any sort of official announcement. But the company is likely to fix that once the update starts to roll out to more countries around the world, and while that moment could be a few days or even weeks away, Samsung is carrying the momentum forward and has updated the Galaxy S9 user manual with references to Android Pie.
Not much useful info in the updated manuals
The Android Pie user manuals are available in English, Dutch, and German, and we should see it coming online in more languages in the next few days. There's nothing the updated manuals say that we don't know, though. The new features are better detailed in our One UI (Android Pie) feature focus series, because the manual talks about things in a generic manner and has a lot of basic info that you have to parse through (like guidance on how to put in a SIM card, which is the same on any version of Android).
Based on Samsung Turkey's roadmap, the Galaxy Note 9's Android Pie update may come out by January 15. The update for the Galaxy Note 8 and Galaxy S8 may follow a month later, although these time frames are all subject to change, as is the case with every new major Android OS upgrade.
