Maybe it could provide an additional channel for even more piece integrity and availability and faster resolution. Instead of relying on AFAIK more or less random checks to detect issues, the satellite would be directed to specific problematic pieces. This approach could also prevent clients from attempting to access non-existent pieces.
For instance, I recently had a lucky piece that was being downloaded at a rate of like 100 times per minute and more. If that piece were to become unavailable, the satellite would continue to send hundreds of clients to the node, resulting in unnecessary and unsuccessful requests. If the satellite would learn fast that the piece does not exist, it could start repair or provide other ips to the requesting clients, serving them better with a higher level of quality.
You are right, I don’t mean these types of messages that’s why I also considered uplink to report back to the satellite. I am specifically talking about the scenario where there is a clients attempt to download a piece and the node cannot provide it because it does not have it.
If there would be a sudden surge of “file does not exist” messages from a particular node on get requests, it likely indicates a problem with that node and its pieces availability that the satellite should be notified about and could take action on. This could provide an additional layer of piece problems actually reported complementing the existing auditing mechanism that finds piece problems randomly.