Google guarantees you’ll get Android software updates for at least two years. From whenever the device becomes available in the Store. The Nexus 6 released in November 2014. Security patches are promised three years from availability or 18 months from when they last sold the device.
The impact on you: Even though the Nexus 6’s end is nigh, the phone may not need to head straight to the recycling bin. They often updated devices beyond the end date, as evidenced by my 2013 Nexus 7. Which still gets monthly security updates and runs the latest build of Marshmallow. It could run out of luck with Android Nougat. But there’s some precedent for a longer lease on life if you just can’t part yet with your Nexus 6.