change_streams_shards_start_in_sync.js temporarily disconnects shard1 from the mongos so that it can test that change streams on sharded collections start in sync with each other. The issue with this is that this will cause the changestream to fail because when the mongos attempts to establish a cursor on shard1, it will get a HostUnreachable error. Instead of rejecting the cursor establishing request from the mongos, shard1 should temporarily hang.