Enum passivity concerns

THRIFT-224 adds the ability to validate enum values. This potentially freezes a given enum for all time. Imagine a scenario where a service starts returning objects with enums that now have new values. For example maybe the service is identifying a new failure type that consumers can now start handling. An existing consumer doesn't know about these values and so they will fail instead of just handling these enum values in a more generic fashion. Was that the intent of THRIFT-224 to lock in enums for all time?