Notice that all of the highlighted databases and server objects belong to the contained availability group, and all other databases and objects are not visible anymore. This is because our “master” and “msdb” databases are now the contained system databases which are separate from the actual instance system databases.
For more details about contained availability groups, such as interoperability support with other SQL Server features and more, check out the official Microsoft documentation at:
But there are several things which are not included with contained Availability Groups. click through for that list.