if ( $wmfRealm == 'production' ) { $wgCentralAuthRC[] = [ 'formatter' => 'IRCColourfulCARCFeedFormatter', 'uri' => "udp://$wmgRC2UDPAddress:$wmgRC2UDPPort/#central\t", ]; }
This dates back to rOMWC89ad4bdd3824: tweak CentralAuth configuration for labs, which predates beta cluster having an IRC server. I don't see any reason for this production conditional today.
Noticed by @Krinkle in the CR for https://gerrit.wikimedia.org/r/c/operations/mediawiki-config/+/670913/