We don't currently have an automated process to inform users about outages recorded in IcM. It is all done manually and in a non-standardized format/timeline.
The goal is to have an engineer create an IcM and send out an initial email to all customers listed in the "Impacted Customers" field that an outage has begun and then automatically send out updates based on the notes in the IcM every 3-4 hours until the IcM is resolved.