On the Admin->Cluster Settings->Global Config->Alertmanager page.  After a user creates or edits an Alert Receiver, or updates the Alertmanager YAML directly;  the Alertmananger Pod attempts to load and parse the updated alertmanager.yaml.  The Alertmananger Pod (alertmanager-main-0) Log shows a success like:

"Loading configuration file" file=/etc/alertmanager/config/alertmanager.yaml level=info ts=2021-01-14T17:30:26.919Z caller=coordinator.go:131 
"Completed loading of configuration file" file=/etc/alertmanager/config/alertmanager.yaml

 Or an error:

level=warn ts=2021-01-14T17:30:34.520Z result=failure addr=alertmanager-main-0.alertmanager-operated:9094 err="1 error occurred:\n\t* Failed to resolve alertmanager-main-0.alertmanager-operated:9094: lookup alertmanager-main-0.alertmanager-operated on 172.30.0.10:53: no such host\n\n"

This alertmananer.yaml load status needs to be displayed on the main Alertmananger configuration page so the user can determin if their last alertmananger.yaml changes were succesfull.

Action Item: follow up with monitoring-team to determine if there is an api we can use to get this information.