We will be enabling canary events for more and more streams in T266798: Enable canary events for all streams. These canary events are needed for ingestion monitoring, but is there any reason to include them in the Refined event tables? All we need is to be able to at least write the _REFINED flag into the hourly Hive partitions. If we filter out canary events for hours with no data, we should still get empty hours but with a complete _REFINED flag.
Users won't have to manually exclude the canary events in their Hive queries if we do this.