Google Nexus 6 was expected to receive an update to the latest version of Android already some time ago. This situation was delayed because, according to Google announcement, the company found a last-minute bug in the update. Finally, update will be available for download in early January.
Thereby, Google Nexus 6 is going to become the oldest phone that will receive an update to Android 7.1.1. This will be probably the last official improvement of Android system for this phone.