Samsung Galaxy Tab A 8.4 (2020) locked to Verizon’s network receives the Android 11-based One UI 3.1 update.
A detailed change log for the update is currently unavailable, but you can expect an updated design along with the usual goodies for Android 11 and One UI 3.1.
That said, Verizon has confirmed in the official post that the new build comes with enhanced quick sharing and enhancements to user interaction for quick panels, toolbars, notifications, and settings. The update also supports the Android security patch level on the tablet for June 2021.
The new firmware comes with version RP1A.200720.012.T307USQU5CUE7 and should reach all the devices in a few weeks. But if you can not wait for the update prompt to appear on your tablet, you can navigate to its Settings > About device > Software updates menu to try to download One UI 3.1 manually.