JConsole supports connect/disconnect/reconnect cycle. Most plugins would likely want to be notified for the connection state property change to deal with the disconnect/reconnect situation.

Currently the plugin would have to override the setContext() method with the following:
   super.setContext(context);
   context.addPropertyChangeListener(listener);

For any plugin which wants to register a listener has to do the same as above.

So having JConsolePlugin to implement PropertyChangeListener will improve the API.