Android M is due for an announcement very soon, but we’re still hearing rumors about what’s going to come with the latest version of Google’s mobile OS. The newest rumor has more to do with how Android M will affect certain Nexus devices than general software enhancements, but it’s still very useful information when considering which device to purchase.
This rumor suggests Google will be enforcing a hard cut-off for software updates for Nexus updates. Nexus devices will receive major software updates for two years, and security updates for three years from new Android version release dates. So a Nexus device that’s released in November of 2015 will receive Android updates through November of 2017 and security updates through November 2018. That’s still a pretty long time and probably longer than anyone is keeping a phone, but that should help those of you that are buying older devices to save money. Google will alternatively provide updates for 18 months after a device is purchased from the Play Store, which seems to indicate that Google will keep a steady schedule for how long they’ll be offering devices through the Play Store.
As for current Nexus devices, this policy means the Nexus 4, Nexus 10, and 2012 Nexus 7 won’t be getting an Android M update. They’ll still be slated for security patches, but no more officially supported major OS updates from Google. The Nexus 5 will see updates up until the end of this year, then security updates for another year, and the newer Nexus 6 and Nexus 9 are good until the fall of 2016.
source: Android Police