Apple has introduced iPadOS 15.4, a major update that brings Universal Control, among other changes. iPadOS 15.4 is a large download and boosts Siri's functionality when offline on a recent iPad Pro too.
https://www.notebookcheck.net/Apple-releases-iPadOS-15-4-to-numerous-iPads-with-Universal-Control-support-enhancements-and-bug-fixes.608338.0.html
Another new iPadOS release and still nothing for the glaring whole of external display support. I know they wanna sell iPad owners a mac for that but some ain't gonna buy when they can get proper external display support on android or windows devices.