Unlocked Samsung Galaxy Note 8 is the last to receive Android 8.0 Oreo in the US23
After AT&T, Sprint, Verizon, and T-Mobile released Android 8.0 Oreo for Samsung Galaxy Note 8 in the last week or so, those who bought the unlocked version can now download and install the update as well.
It appears that the update weighs in at 1.1GB and includes the March security update. Don't expect any other changes like the ones included in the Android 8.0 Oreo update for the carrier-branded models.
Keep in mind that since this is a staged roll-out, it might take up to a week to propagate to all unlocked Galaxy Note 8 units in the US, so you might have to wait a bit longer if it doesn't show on your phone right away.