I'm leading the work for mongosync's embedded verifier (REP-2496), and it would be very helpful to us if we could get the collectionUUID field in all change stream events for server version 5.0.

From a discussion in the #change-streams channel, it seems like this is controlled by a single if statement, though Slack discussion noted that there may be some difficulty in that showExpandedEvents is not supported pre-6.0.