On 16th January, HMD Global updated the very useful update tracking page for Nokia Android devices. The update page shows for which device (based on the build number) did an update rollout start.
On the webpage you can check if an update was released for your device based on the build number you can find in the about section in settings. For example, we can see that Android 9 Pie was released for Nokia 8 Sirocco with build number 00WW_4_120, while devices with 00WW_3_10D are still waiting for HMD to push the button. The problematic 00WW_2_22E version of Nokia 6.1 is also without Pie, but the tracker shows that it received regular security updates over the past few months.
Recently HMD posted an infographic about how the process of Android Pie update Works, so if you’re interested you can check that here.