HMD Global Chief Product Officer Juho Sarvikas has recently confirmed that the Nokia 2 will jump straight to Android 8.1 to get advantage of the memory optimization features, but the Nokia 3 will also get the first Oreo beta soon.
https://www.notebookcheck.net/Nokia-3-Oreo-beta-coming-soon-Nokia-2-to-jump-straight-to-Android-8-1.280462.0.html