Although Sony promised to deliver Android Pie on October 26 to quite a few supported Xperia handsets, the update was a bit delayed. Fortunately, the Xperia XZ Premium, XZ1, and XZ1 Compact are now finally receiving the Android 9.0 firmware. Obviously, the other supported Xperia devices should get the update in the coming months as well.
https://www.notebookcheck.net/Android-Pie-finally-hits-the-Sony-Xperia-XZ-Premium-and-Xperia-XZ1.360441.0.html