Samsung recently announced a list of its devices that will receive an update to Android 8.0, via its Canadian website.
Here's the official list:
|March 19||Samsung Galaxy S8, S8+|
|March 28||Samsung Galaxy Note 8|
Samsung Galaxy S7, S7 Edge, A5,
Tab S3 9.7
|"Later in 2018"||
Samsung Galaxy Xcover 4, A8 (2018), J3 Emerge,
Tab A 8.0 (2017), Tab Active 2, Tab A 10.1 (2016)
This timeframe does not necessarily apply globally, as it may differ slightly - European and Indian models of the Galaxy S8 and S8+ are already running Oreo since last month, as are select Note8 devices in the US in a slow rollout. It will accurately apply only to Canada, though it may be used as a rough frame of reference for other regions.