The Go Driver does not publish a TopologyDescriptionChangedEvent when closing a topology, despite marking the topology as unknown. Speaking with boris.dogadov@mongodb.com , it appears that .NET and Node both publish in this case. I’m fairly confident the Rust driver also publishes. More than likely, this publication is not required and the specifications will be updated to remove this log from the expected messages. Until then, the Go Driver has opted to remove this code. This ticket is a placeholder so that we don't forget to add it back.