https://wccftech.com/not-surprisingly-pixel-and-pixel-xl-wont-be-updated-to-android-11-time-to-upgrade/

Google has released the developer preview for Android 11 for Pixel handsets earlier than expected. This means that the owners of the Pixel 2, 3, 3A, and 4 can manually flash a full system image onto their devices. Unfortunately but quite predictably, the original Pixel phones that were released back in 2016 will not be getting the latest version of Android.

Although the first-generation Pixel devices were only guaranteed Android updates until 2018, Google showed generosity by rolling out Android 10 to them in 2019. However, the support is now finally ending, as the Android 11 developer preview is not available for the first-ever Pixel smartphones. It doesn’t really come as a surprise, but the lack of developer preview images kills any remaining hope of a new OS update.