This extension is one of the oldest extensions we still have in production and currently does not have a maintainer. FlaggedRevs has been the cause of several incidents and visible regressions specially since software decays and our environment constantly changes.

Another problem with this extension is its scope, while most of its functionalities are not enabled in WMF production or enabled in a very small set of wikis (e.g. multiple dimensions was enabled only in Hebrew Wikisource but they agreed to disable it). This has made maintaining the extension a tall order (more of a nightmare). In other words, this extension does too many things and does none well.

To move forward, we are removing barely used functionalities of this extension. Including support for multiple dimensions, multiple tiers, several one of its special pages and more to make it less of a burden to maintain and improve. It would simplify its logic drastically and will enable us to rework its old interface, fix several deprecated code that this extension is the last to block their removal (like action=ajax), reduce the number of issues/incidents/regressions caused by this extension and much more.

Users in most wikis that have this extension enabled (including English Wikipedia and German Wikipedia) won't see a difference but for example, users won't be able to mark a revision as "good quality" or "average quality" anymore in English Wikibooks or Finnish Wikipedia. The "checked/stable" status will stay though.

This is also to notify third party installations of this extension that this will happen from release 1.36 so if you need to have some of its features we are removing, please fork.

To see the discussion around this, take a look at https://phabricator.wikimedia.org/T185664

Thank you for understanding and sorry for any inconvenience.
Amir (he/him)