The author does mention that the OS appears to be performing a sort of batching or aggregation of fsyncs after reviewing the test results and concludes that more than 1000 fsyncs are occurring per second. I’ve also confirmed this by running some benchmarking on EC2 instances with gp2 volumes: https://justincartwright.com/2025/03/13/iops-and-fsync.html
You do have to conform to the communication norms of whatever group you're communicating with.
That's an excellent point. It does make sense to observe the way certain common forms of acknowledgement are being used within different context to understand the way that the group interprets them.