Galaxy S8 and S8+. The Korean tech giant launched a beta program for the 2017 flagship pair and managed to dish out three beta builds to date, yet we didn't really have an ETA for the official premiere of the Oreo update.
Until now, that is. In response to a query about the ETA for the next patch, a UK Samsung Beta community admin revealed that an official Oreo version for the S8 and S8+ should be ready by the end of next January. The admin also noted that the rollout could be delayed to early February if any unexpected issues arise.
Finally, the post mentions that the fourth beta preview of the software should arrive "very very soon". While "soon" is never a warrant for any particular date or time, suspect that beta 4 will go live in the next few days.
After the Galaxy S8 and S8+ get updated to the latest major version of Google's mobile OS, the Galaxy Note 8 should be next in line to receive the Oreo treatment.