In the next few months, the Nokia 2017 product line (including Nokia 3 / Nokia 5 / Nokia 6) will be available in the world on sale. HMD previously said that all three devices factory default run native Android 7.0 Nougat system, and will get regular software updates. Today, Nokia Mobile in tweets to further confirm that these phones will be "l" and "security update."
Nokia did not say how long these new devices could be updated in the future. Often, Android phones will receive a 2-year maintenance update after the sale, but not for the low-end entry market. So basically can confirm Nokia 6 update will be supported to 2019, but Nokia 5 or Nokia 3 is uncertain.