The latest smartphone from Asus to get the Android Oreo update is the Asus ZenFone 3 Max. The update comes in the form of Android 8.1 Oreo.
The software update for the ZenFone 3 max comes with the software version 15.0200.1807.406 and it also includes a new version of Asus’s own custom user interface ZenUI 5.
There are two different variants of the Asus ZenFone 3 Max, one with the model number ZC520TL and the other with the model number ZC553KL, the update has been released for the device with the model number ZC553KL so far, it is expected to land on the other handset some time soon.
You can check to see if the Android 8.1 Oreo update is available for your Asus ZenFone 3 Max from the settings menu on your device. To install the update go to Settings > About > System update.