If you mark a view table(view.table1) materialized true, the preview option is grayed out as it should be, but if you then create another view table(view.table2) that uses the above materialized view table, the preview option is available but errors with:
org.teiid.runtime.client.TeiidClientException: java.lang.RuntimeException: Remote org.teiid.api.exception.query.QueryPlannerException: Group does not exist: view.table1

We should document this that this is not possible and/or a better error description would be nice and/or disable the preview data option for a view model which is based on view model which has materialized set to true.