Gone but not forgotten, the two year-old OnePlus 3 and 3T are being updated right now to OxygenOS 5.0.3, containing Face Unlock features and May security patches.
The OnePlus 5T follows in the footsteps of the 5, 3T and 3 (instead of the other way around), scoring stable over-the-air Android 8.0 Oreo goodies today.
OnePlus says the OxygenOS 5.0 update has a "bug" that needs fixing and, thus, will not be available anymore until things are fixed.
The newest OnePlus phone didn't launch with Android Oreo, but it is soon to get it with the beginning of this beta program.
OxygenOS 5.0 is in, but not Face Unlock just yet. The much-desired feature is going to be out in a future software update.