While this article leaves it ambiguous, the incident status report[1] makes it clear that customers can expect an actual postmortem:
"We will conduct an internal investigation of this issue and make appropriate improvements to our systems to help prevent or minimize future recurrence. We will provide a detailed report of this incident once we have completed our internal investigation. This detailed report will contain information regarding SLA credits."
"We will conduct an internal investigation of this issue and make appropriate improvements to our systems to help prevent or minimize future recurrence. We will provide a detailed report of this incident once we have completed our internal investigation. This detailed report will contain information regarding SLA credits."
[1] https://status.cloud.google.com/incident/cloud-networking/19...