MCD will send an alert when a rendered machine config is missing 

The alerts describes the following 

summary: "This keeps track of Machine Config failures. Specifically a common failure on install when a rendered Machine Config is missing. Triggered when this error happens once."
            description: >-
              Could not find config {{ $labels.mc }} in-cluster, this likely indicates the MachineConfigs in-cluster has changed during the install process. 
              If you are seeing this when installing the cluster, please compare the in-cluster rendered machineconfigs to /etc/mcs-machine-config-content.json

It is possible that admin may not be able to interpret exact action to be taken after looking at MCD pod logs. Adding runbook (https://github.com/openshift/runbooks) can help admin in better troubleshooting and taking appropriate action.