Apple continues to test iOS 16.6 with the release of a new test build of the software.
Here's What We Know
The update has been released with the iOS 16.6 Beta 2 number. The firmware can only be installed by users with a developer account for now. A test system for everyone will be released a little later.
As for the list of changes, Apple unfortunately did not disclose it. Most likely, the software contains minor bug fixes and system optimization.