Google's update schedule has been mostly the same with any Nexus device in the past: Android updates for two years, security updates for three years or 18 months after the Google Store runs out of stock. Honestly, there's nothing surprising about these numbers, only that Google has posted them onto its Android support page. The Google Pixel was released in October of last year, so the Pixel and Pixel XL will both receive "guaranteed" Android version updates through October 2018. Notice Google says "Guaranteed" because it could decide it wants to update the Pixel to the most current...
Source: http://www.gsmarena.com/google_will_guarantee_pixel_android_updates_through_2018_security_patches_through_2019-news-24781.php
