The Samsung Galaxy Tab S3 appears to have gotten one step closer to receiving the official Android Oreo update, as the tablet was recently tested by the Wi-Fi Alliance running the aforementioned mobile OS version. Specifically, as of this writing, the regulatory agency seems to have tested only the LTE variant carrying the model number "SM-T825C" which is meant for China and Hong Kong, but there's no reason to believe that the Wi-Fi-only "SM-T820" alternative won't receive the same treatment in the future. Exactly when Android Oreo will land on the Galaxy Tab S3 is unknown, but reports of the slate being scheduled for the update have existed for more than a month now and it seems that Samsung is indeed making progress towards expanding the availability of Oreo onto more devices it launched in 2017.
The Samsung Galaxy Tab S3 was unveiled in February 2017 and launched a couple of months later running Android 7.0 Nougat out of the box. It remains the company's top-tier Android-running tablet powered by Qualcomm's Snapdragon 820 chipset, though there have been reports of a sequel possibly being underway. The so-called Samsung Galaxy Tab S4 bearing the model number "SM-T835" was discovered in the database of benchmarking tool HTML5 earlier in February, where the device ran Android 8.0 Oreo out of the box while employing a display with a 16:10 aspect ratio and the newer Snapdragon 835 chipset from Qualcomm. There's not much known about the alleged Samsung Galaxy Tab S4 officially, so there's no way to determine whether the existing Galaxy Tab S3 will receive the Android Oreo update before or after its supposed sequel will be introduced to the Android tablet market.
In any case, Samsung has already begun rolling out the Oreo update onto several smartphone models launched last year, including the Galaxy S8 flagship series, and more recently, the stylus-enabled Galaxy Note 8. And with the launch of the latest Samsung Galaxy S9 flagship phones out of the way, the OEM could now find the necessary time and resources to start updating its premium tablet soon. It remains to be seen what new features will be introduced by Android Oreo on the Samsung Galaxy Tab S3, but presumably, the OS will be accompanied by some changes to the user interface, better multitasking, and improved performance and stability.