The cluster wide read and write concern code has logic in a sharded cluster to run commands on the config server at startup and replica set reconfig and SERVER-72454 disabled the startup command when running on a catalog shard (ie user data bearing config server). The startup logic seems unnecessary because on a catalog shard the default RWC should exist locally and the local defaults cache should be enough, but the purpose of this ticket is to verify that and any other behaviors related to default RWC on a catalog shard.