It looks like since the 2.12 upgrade, @gerritbot does not add Patch-For-Review and a comment including a link to the patch URL anymore. See https://phabricator.wikimedia.org/p/gerritbot/
Examples: https://phabricator.wikimedia.org/T139491#2491161 or https://phabricator.wikimedia.org/T140458#2491159 (the patches do include Bug: T9876543 in the commit message).