Thread:Sannse/@comment-4828844-20140408074016/@comment-366087-20140408093459

Actually, in checking… you have the wrong content in MediaWiki:Welcome-user, which should only have as content
 * @latest - most recently active admin, or Wikia staff if no admins have been active in 60 days
 * @sysop - most recently active admin (with no fallback to Wikia staff)
 * A specific username - in plain text, not as a link
 * @disabled - entirely turn off welcoming of new users

What you have there should be in MediaWiki:Welcome-message-user, or perhaps MediaWiki:Welcome-message

Because MediaWiki:Welcome-user does not have the proper variable set, instructions which depend on it fall back to the Staff Defaults.