For backward compatibility we tried to keep the previous named certificates the way they were:

https://github.com/openshift/cluster-etcd-operator/blob/master/pkg/operator/starter.go#L614-L639

Many of those are currently merely copied with the ResourceSyncController and could be replaced with their source configmap/secret. 

This should help with easier understanding and mental load of the codebase. 

Some replacement suggestions:

• etcd-serving-ca -> etcd-ca-bundle
• etcd-peer-client-ca -> etcd-ca-bundle
• etcd-metrics-proxy-serving-ca -> etcd-metrics-ca-bundle
• etcd-metrics-proxy-client-ca -> etcd-metrics-ca-bundle

AC:

• replaced the above suggestions 
• updated static pod manifests and references in backups
• updated docs/etcd-tls-assets.md