See https://issues.redhat.com/browse/WFLY-20374?focusedId=26554447&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-26554447

Right now a number of testsuite modules use slimmed servers when they could be using complete installations, leaving the slimmed testing to ts.layers.

In other cases. slimming is the only valid approach, but whether the module executes via ts.preview vs ts.layers is the question.

Perhaps the thing to do is get rid of -Dts.preview and use -DallTests instead, making the modules that execute with -DallTests analogous to what executes with ts.preview.