Hi,
This behavior is subject to change as we make changes to our video and web systems.
Each ingested stream of video has a unique ID. We go through a process called transcoding, which takes the source and splits it into multiple different quality video files. Since the original ingest is not disrupted, the ID remains the same.
This however does change properties in our internal systems, hence the updated_at field changing. The creation of highlights does not affect the original video stream, and should not affect the ID or updated_at, but would have some properties of the parent video stream.
Past broadcasts are raw copies of the post-transcode video. Since there is no standard for “have the first half of a VOD be source, and the second half be split into qualities” it is split into a new file.
Hope that helps, please ask for any clarification needed 