To the line:
https://github.com/Jasig/cas/blob/master/cas-server-core/src/main/java/org/jasig/cas/logout/LogoutManagerImpl.java#L120

This block shows that we are simply collecting logout requests, and only perform back-channel processing if the service is configured to do so. 

So, here at CASImpl level this would be an unfair assumption to display the debug message that the component is going to perform back-channel logouts. I think it should be adjusted to say something like `Processing logout requests... etc`