[[https://github.com/wikimedia/mediawiki-extensions-OAuth/blob/c88313c245e1f428dfa2003b0cefc86b12d6e2e5/frontend/MWOAuthUI.hooks.php#L183|MWOAuthUIHooks::onBeforeCreateEchoEvent]] contains this snippet:
$notificationCategories['oauth-admin'] = array( 'tooltip' => 'echo-pref-tooltip-oauth-admin', 'usergroups' => $wgOAuthGroupsToNotify, );
This works locally in vagrant, but not on meta - $wgOAuthGroupsToNotify is empty.
tgr@terbium:~$ mwscript eval.php --wiki=metawiki > var_export($wgOAuthGroupsToNotify); array ( 0 => 'oauthadmin', ) > var_export($wgEchoNotificationCategories['oauth-admin']); array ( 'tooltip' => 'echo-pref-tooltip-oauth-admin', 'usergroups' => array ( ), ) > \MediaWiki\Extensions\OAuth\MWOAuthUIHooks::onBeforeCreateEchoEvent( $not, $cat, $i ); > var_export( $cat['oauth-admin'] ); array ( 'tooltip' => 'echo-pref-tooltip-oauth-admin', 'usergroups' => array ( 0 => 'oauthadmin', ), )
Maybe related to the fact that Oauth uses extension registration but Echo does not. BeforeCreateEchoEvent is called from ExtensionFunctions though, which should in theory be late enough so not sure what is going on.