Oak Observation support exposes a EventListenerMBean  which provide quite a bit of details around registered observation listeners. However in a typical application there would be multiple listeners registered. To simplify monitoring it would be helpful to have a consolidated view of all listeners related statistics.
Further the stats can also include some more details which are Oak specific
- Subtree paths to which the listener listens to - By default JCR Api allows single path however Oak allows a listener to register to multiple paths
- If listener is enabled to listen to cluster local and cluster external changes
- Size of queue in BackgroundObserver
- Distribution of change types present in the queue - Local, External etc