In most cases, using moveChunk with find if the shard key is hashed is a user mistake (in face, our docs explicitly say not to do so). However, when a user does this, it can end up with unexpected behavior that makes debugging the problem difficult. A user tried to use sh.moveChunk on a collection with a hashed shard key, and from the user perspective nothing happened because the chunk that the move chunk command chose was already on the correct shard.

It would be helpful to users to emit some warning saying that using find with a hashed shard key is not recommended and that they should use bounds instead.