I don’t see any value in knowing before the pilot knows. I’ve mostly flown American the past few years and with their app I get updates about delays and gate changes on my phone just fine. I suppose there might be some advantage to getting the notification a bit earlier, but I doubt that they can reliably give information faster than the airline itself.
I think I figured it out - if you can figure out a cancellation before everyone else you can get to the counter and get on another flight before everyone.
I've had once cancellation in my life so I see why the need hasn't presented itself very loudly.