In cluster_list_indexes_cmd.cpp, cursorCommandPassthroughShardWithMinKeyChunk takes separate routingNss (buckets namespace for shard routing) and cursorNss (user-facing namespace for cursor responses). This was introduced to support legacy timeseries collections where the routing namespace differs from the user-facing namespace. Once 9.0 becomes last LTS and all timeseries collections are viewless, these will always be the same and should be collapsed into a single nss parameter.