The November 2019 security updates for Android are now available for the Pixel 2, Pixel 2 XL, Pixel 3, Pixel 3 XL, Pixel 3a, Pixel 3a XL, Pixel 4, Pixel 4 XL, and the Essential Phone. Noticeably absent from this list are the original Pixel and Pixel XL, which are no longer supported by Google. This security update includes several feature improvements, including at least part of the promised fix for the Pixel 4's 90 Hz display woes.
https://www.notebookcheck.net/November-2019-Android-security-update-now-available-for-Pixel-phones-but-not-the-original-Pixel.441213.0.html