Enabling FlaggedRevs for the MediaWiki namespace may have unforeseen consequences for GEI users that I'd like to see discussed before this goes anywhere.

I would be very cautious about enabling FlaggedRevs for NS_MEDIAWIKI.

At best it would do nothing, but give people a false sense of security that their edits were not "live" yet when they really were.

T226054 The problem is that FlaggedRevs is already included in MediaWiki and you need to confirm revisions on a mass of pages. But this is not possible because the confirmation button is disabled. Can to approve this message from one page, but it will appear again and again, since Mediawiki pages cannot be patrolled.
During the year there was no solution to this problem.

I nonetheless think we should be very cautious enabling FlaggedRevs in NS_MEDIAWIKI.

In fact, flagged revisions is hardcoded to not allow this:

global $wgFlaggedRevsNamespaces;
foreach ( $wgFlaggedRevsNamespaces as $ns ) {
        if ( MWNamespace::isTalk( $ns ) ) {
                throw new Exception( 'FlaggedRevs given talk namespace in $wgFlaggedRevsNamespaces!' );
        } elseif ( $ns == NS_MEDIAWIKI ) {
                throw new Exception( 'FlaggedRevs given NS_MEDIAWIKI in $wgFlaggedRevsNamespaces!' );
        }
}

Seems, it's a bug in code. How can resolve or get around this issue?
Which code show the revision requirement for this NS?