Good news: org.jboss.errai.container.CDIServletStateListener is officially deprecated in Errai 2.2.0, and completely removed in Errai 3.0.x.
You can just change your <listener-class> entry to org.jboss.weld.environment.servlet.Listener and go back to your original plan of hooking into AfterDeploymentValidation.
Hope that helps,
Jonathan, good to hear the offical statement After we upgraded to 2.2.0 I tried the default listener and everything works fine now. Thanks a lot for help.