The issue for them is actually written news. They might be able to embargo broadcast news, but they can’t really do anything about me getting a news alert on my phone the minute I wake up that says “Biles pulls out of Team Event at Olympics,” or “Suni Lee wins All-Around Competition at Olympics,” or “Rapione scores goal to take US Women into semifinals.” While that might encourage someone to watch the prime time coverage; it might also make them skip watching the Games for day since they already know the outcome.
Plus, they might be able to embargo broadcast news from showing footage from an event, but they can’t really stop them from reporting on results, controversies, etc. with generic images or newsflashes/chirons.