With the beginning of a new month, Google religiously pushes its monthly security patch for all its Google Pixel smartphones.
The devices covered in this March 2020 security update include the Google Pixel 4 and 4XL, 3, 3a, 3XL and 3a XL and Google Pixel 2 and 2XL. Verizon has sent the updates as OTA and they should have arrived on your devices by now. Verizon mentions on the update pages that all these devices are getting their latest software update patches alone. However, Google is reported to have addressed some reported issues in most of the models.
Google Pixel 4 and Pixel 4 XL
This 5th system update from Verizon for these 2019 models from Google contain the March 2020 Android security update patch. A chart (added below) shows that these two latest releases from Google, the Pixel 4 and Pixel 4XL have received maximum fixes for various issues. These range from certain issues in the camera section to face unlocking and motion sensing, etc. Verizon has not explained these changes in detail.
Google Pixel 3a and Pixel 3a XL
Google Pixel 3a and 3a XL are getting their system update 11 from Verizon now and the main description of this update is the same, latest Android security update patch for March 2020. Here too, there are some audio and video related improvements and fixes for Bluetooth connectivity issues.
Google Pixel 3 and Pixel 3XL
Being models of older vintage, the Google Pixel 3 and Pixel 3XL have received 17 system updates already from Verizon and this is the 18th. Many improvements and fixes mentioned above for the later models are included for these devices too apart from the March 2020 Android security update patch.
Google Pixel 2 and 2XL
The Google Pixel 2 and 2XL smartphones are also receiving performance enhancements and fixes for diverse issues like the later editions. The main change is the latest March 2020 Android security update. These are system update No.29 for these phones from Verizon.
You will notice that the build number is common for all the devices. This is how Google assigns the version number.