There was word a while ago that the Nokia 8 would have Treble implemented on the final build of its Oreo update but that is not to be, as company CPO Juho Sarvikas has confirmed the lack of Treble on any Nokia device, much like we saw from OnePlus a while ago.
https://www.notebookcheck.net/HMD-executive-confirms-that-current-Nokia-devices-will-not-get-Treble.268348.0.html