According to Google's latest Android usage report, the latest version, Oreo, is on little more than 1% of Google Play devices. One might have speculated that that number was about to go up last week when Samsung started its rollout of 8.0 Oreo for the Galaxy S8 and S8+ in select markets like Turkey, Norway, the UAE, India, Belgium, Germany, France, and Poland.
As it turns out though, the company has pulled the update, as reported by SamMobile. It's currently unknown why the rollout has been halted, although it seems likely that there's a major bug that wasn't caught in the months of beta tests, that the company wants to fix. Those that have already installed the update will be unaffected by this, except for, presumably, whatever bug stopped the rollout.
The firmware files are identified by the string G950/G955-FXXU1CRAP (yes, we see it too), and have been removed from Samsung's servers. It seems likely that the rollout will once again resume soon enough, once the company fixes whatever's wrong.