It has been voted on https://forum.xwiki.org/t/stop-storing-notification-event-statuses-in-subwiki-databases/13848 to not fix this. A workaround if someones needs this is now to perform the query in Solr: it can be done also in main DB but we might stop soon to store events information in DB (see this proposal: https://forum.xwiki.org/t/move-legacy-storage-of-notifications-to-an-extension-and-stop-bundling-it/13849/)