Got an e-mail from Nokia. "Many thanks for being part of the Android™ 9 Pie Nokia phones beta labs program with your Nokia 8.
If you wish, you can roll back to Android Oreo™ to get the official Android 9 Pie release once it is approved in your market – just remember to back up your data because rolling back will erase your apps and files. That said, there’s no need to take action if you don’t want to – the only difference between the Android 9 Pie beta build and the upcoming official market release is the Feedback App. Users on the Android 9 Pie beta software will receive one security update before the next maintenance release."