The Nokia 3.1 Plus is receiving Android 9 Pie. HMD made a big deal of supporting its phones for three years, two of software updates and an extra year of security updates. The 3.1 Plus was launched in October last year, it has a long life ahead of it.
They are the usual new gesture UI, the Adaptive Battery and Adaptive screen brightness, Predictive Application Actions too. The security patch is bumped up to February 2019