When a shard processes an operation with available read concern, the shard version attached to the command are ignored and, from the point of view of the CollectionShardingRuntime, the Collection is considered as if it was UNSHARDED (getCollectionDescription, getOwnershipFilter). For views over sharded collections with available read concern, we believe that the operation can be solved on the primary shard because the CollectionShardingRuntime says that the collection is UNSHARDED, avoiding to use the kickback machinery.