Unless I missed something, org.jboss.as.test.shared.util.LoggingUtil adds nothing to what wildfly-core-testsuite-shared's org.jboss.as.test.shared.logging.LoggingUtil does, except in some methods it takes ManagementClient as a param instead of ModelControllerClient. But it does nothing with the ManagementClient except call ManagementClient.getModelControllerClient(). Otherwise it's just a lot of duplicated code.

OTOH the WildFly Core class has useful methods that people may not see exist if they find the full WF class and reasonably think that's the 'best' one to use.