I did write to them when I was frustrated when I can't see women's 53 kg in weightlifting, and they replied:
Thank you for contacting the Olympic Channel about YOG live streams and we hear your frustration.
The Olympic Channel is streaming all events that the Host Broadcaster and IOC are producing. Unfortunately, production is not available to us for all 239 YOG events. If you do not see your desired event listed, then a live stream is not available. Although we realize it is not the same as watching competition, we will provide coverage of all sports at the YOG, including those without live streams, via highlights on our 24/7 YOG Channel.
Hope this helps and enjoy the Games.
Hope this answers