Currently we report the optime of each node in the replicaset and the lastCommittedOpTime of the primary, but we don't report the readConcernMajorityOpTime of a node if it's the primary. The lastCommittedOpTime can refer to the optime of operations that don't actually exist a secondary reporting replSetGetStatus. This should refer to the OpTime used for readConcern: Majority calls, (the committed snapshot OpTime) that exists on the reporting node. If readConcern is turned off, this field should be omitted.