Looks like Samsung want to waste no more time providing Android Pie update on its last year devices, because recently the Quad Camera phone Galaxy A9 (2018)/A9s and A8 (2018) has recently been certified by Wi-Fi Alliance (WFA) to receive the One UI.
Multiple models of the Galaxy A9 (SM-A920F) including the Chinese version A9s (SM-A9200) and the Galaxy A8 (SM-A530F) has been certified by WFA with Android 9.0 Pie on board, indicating that these phones are ready to receive the new Operating system.
Also, the Certificates includes models number from all of the regions where the phones were launched.
The Galaxy A9/A9s comes preinstalled with Android 8.0 Oreo and the Galaxy A8 comes with Android 7.1 Nougat. Although the official schedule of the Android 9.0/One UI for A9 is noted for April 2019 but it seems like it may come early.