During the works on EAP7-1666, there has been added a smallrye-reactive-messaging-kafka-api module into the WildFly server, see this module.xml.

This module has been added with <property name="jboss.api" value="private"/>. We shall review this since classes from this module shall be used by user in deployment. Weird is that I didn't notice any warning regarding the usage of a private API, that shall be generated based on this code in ModuleLoadService.java.