The final step of the shard split critical section must wait for a no-op write to majority commit on the recipient primary to prevent invariant rollback of the stable_timestamp on the recipient. If the node selected to be recipient primary goes down after winning an election, another node with a lower lastApplied may win a subsequent election and force the original primary to rollback when it comes back online. Waiting for the selected recipient primary to majority commit a no-op entry while its primary ensures future elections will not cause this rollback.