The Android Go handsets Samsung Galaxy J2 Core and Galaxy J4 have recently been certified by the Wi-Fi Alliance with Android Pie firmware onboard. However, the arrival of the update might take a while. The Galaxy S8 and Galaxy Note 8 were certified back in November with Android 9.0 onboard, but the update is not ready for them yet.
https://www.notebookcheck.net/Samsung-Galaxy-J4-2018-with-Android-Pie-gets-certified-alongside-the-Galaxy-J2-Core.405591.0.html