It turns out that the WKINIT-2 can also apply to the initialization of the legacy event stream, defined here : https://github.com/xwiki/xwiki-platform/blob/master/xwiki-platform-core/xwiki-platform-legacy/xwiki-platform-legacy-events-hibernate/xwiki-platform-legacy-events-hibernate-api/src/main/java/org/xwiki/eventstream/store/internal/EventStreamStoreInitializer.java