The Samsung Galaxy Tab A 8.4 (2020) locked to Verizon's network is receiving the Android 11-based One UI 3.1 update.
A detailed changelog of the update is currently unavailable, but you can expect refreshed design along with the usual Android 11 and One UI 3.1 goodies.
That said, Verizon, in the official post, has confirmed that the new build comes with enhanced Quick Share and improvements to user interaction for Quick Panel, Toolbars, Notifications, and Settings. The update also bumps up the Android security patch level on the tablet to June 2021.
The new firmware comes with version RP1A.200720.012.T307USQU5CUE7 and should reach all the units in a few weeks. But if you can't wait for the update prompt to pop up on your tablet, you can navigate to its Settings > About Device > Software updates menu to try downloading One UI 3.1 manually.