PSA for Beta Users: Avoid Using Smart Switch
If you are a Galaxy S8 or Galaxy S8+ Android Oreo beta user and you notice an update on Samsung's Smart Switch solution, avoid it.
It looks like some Galaxy S8 users are being prompted to install new firmware via Smart Switch. That would be fine if it was the final version of Android 8.0 Oreo, but it's not.
Instead, it looks like Smart Switch is trying to revert Galaxy S8 devices back to an older version of Android Nougat. And that too would be fine if it didn't mean the whole device got wiped in the process. The final Oreo release won't wipe your phone's data.
So unless you want to deal with a major headache, or you actually want to return to Android Nougat, you're advised to avoid any software updates coming from Smart Switch until further notice.