Chunk migration commit was made to fail if run concurrently with a resharding operation as part of SERVER-50027. This is believed to be sufficient for resharding's correctness; resharding depends on chunk ownership not changing for the duration of the operation but it doesn't depend on the chunk map staying constant. Commands such as refineCollectionShardKey and splitChunk should technically be safe if run concurrently with resharding. We should add some targeted testing to demonstrate so or add logic to prevent these commands regardless and test that behavior instead.

It would be worth auditing the list of data placement commands as part of this ticket to be doubly sure. updateZoneKeyRange is another command which had come up during the project scope.