The $changeStream stage in the aggregate command run by the ReshardingChangeStreamsMonitor is configured as follows:

• When monitoring the source collection, "showMigrationEvents" is set false to avoid range deletions, whereas "showSystemEvents" is set to true to capture the 'reshardBlockingWrites' event.
• When monitoring the resharding temporary collection, "showMigrationEvents" is set to true since events (including the 'reshardingDoneCatchUp' event) against the temporary collections all have fromMigrate": true, whereas "showSystemEvents" to false since the monitor doesn't need to watch any system events.

This is tested end-to-end when the verification is enabled in SERVER-98586. However, we should still add unit tests for this in ReshardingChangeStreamsMonitorTest.