This check used to be written as "dbPrimaryShard.has_value() ? ...", since the DSR is supposed to be authoritative here and thus dbPrimaryShard should have value iif the current shard is the DB primary. After _shardsvrSetAlloChunkOperations is broadcasted to all shards in SERVER-128052, this appears not be always true in the presence of setFCV. This ticket is to investigate this issue.