Script that can be copied into phpsh to see the problem
EventLogging modules use the revision as the modified time (except on error, in which case 1 is used).
The problem is that ResourceLoaderStartupModule considers $wgCacheEpoch (https://git.wikimedia.org/blob/mediawiki%2Fcore.git/ae03d1a0a38b7aa60a02843ef1e55a680c0166f2/includes%2Fresourceloader%2FResourceLoaderStartUpModule.php#L151). The effective mtime is:
max( $moduleMtime, wfTimestamp( TS_UNIX, $wgCacheEpoch ) );
The default $wgCacheEpoch (in DefaultSettings.php) is '20030516000000', which translates to 1053043200, already far greater than the latest revid on Meta. On a real wiki, it will be higher still, since it can be manually set (it is '20130101000000' in production) and on non-production wikis effectively defaults to the mtime of LocalSettings.php.
This means changes to the schema never actually update the effective version. I caught this while using the localStorage module storage (even hard-refreshing, which ideally should not be necessary, does not work around this problem).
I'm planning to fix it by adding the revid to the UNIX time version of the epoch.
Version: unspecified
Severity: normal
Attached: