The major US carrier AT&T, Verizon, Sprint, and T-Mobile have released the Android 8.0 Oreo Update to their Galaxy S7 and S7 edge variants back in June. After a long wait of around one and half month, since the first update rolled out in the US, Samsung is now releasing updates for unlocked S7 and S7 edge models (SM-G93xU).
Generally, owners of US unlocked S7 face this problem when updates are released they have to keep waiting for the updates. As a result of this most of the US, users prefer to opt for the carrier models. This ensures they receive the updates on time.
The Android 8.0 Oreo Update released carries build number R16NW.G93xUUEU4CRG2. It comes with the April security patch and comes around 1.5 GB in size. The current Oreo update features Autofill, picture-in-picture, notification dots, as are Samsung-specific ones like Dual Messenger and high-contrast keyboard options. You can update your US unlocked S7 by manually check in settings. Source: r/GalaxyS7