The update for Nokia 4.2 is 440MB in size and the changelog mentions UI enhancements and stability improvements, as well as the already mentioned May update. To check the availability go to Settings->System->System Update and do leave a comment if you have a 4.2 and an update is available for the device.
Nokia Mobile also updated their Update Tracker site on 20th May 2019. The update tracker now includes the Nokia 3.2 and the Nokia 4.2, which fully complete the list of all announced Nokia Android smartphones thus far. You can check Nokia Mobile’s update tracker here.
We also created an update tracker to better track all the Devices and updates they received and you can check it here.