There are three changes, the first two are breaking.
The two breaking changes are in three command-monitoring tests: "bulkWrite.yml", "unacknowledgedBulkWrite.yml" and "insertMany.yml":
The format of the "requests" array and "ordered" option changes from this:
This brings Command Monitoring tests in line with the Retryable Writes and forthcoming Transactions tests.
The non-breaking change is in the Retryable Writes tests:
Before, the tests said in prose that all MongoClients should be created with retryWrites=true. Now, the tests include the following YAML:
The clientOptions are the same for all Retryable Writes tests. Interpreting this field now will prepare you for the Transactions tests, which make real use of the field.