ReplicationCoordinator::checkCanServeReadsFor checks that the node is currently in a readable state. Callers of this method are required to either be holding locks or within a lock-free operation context. Read commands and getMore all call this method after having acquired AutoGet/ShardRoleAcquisition. Therefore, it would make sense to fold this check under the ShardRole API.

Similarly, write_ops_exec::assertCanWrite_inlock is called on write commands (e.g. here). This could also be folded under the ShardRole API.