Cloning from T53418.
Echo should support global account rights change notifications.
T53540: Support cross-wiki rights change notification in Echo
T53418: User rights hook doesn't take into account cross-wiki or global user rights changes
Prioritization and scheduling of this bug is tracked on Mingle card https://mingle.corp.wikimedia.org/projects/flow/cards/225
Change 88683 had a related patch set uploaded by Alex Monk:
Support global group change notifications
Un cookie-licking, it shouldn't be too hard to pick up my patch and move it into CentralAuth...