I don't believe that is necessarily true. There are definitely some contractual things that keep people from broadcasting what is local, on IHeart Radio. I tried listening to KXIC once online, knowing full well they would be doing the Iowa dual that night. First time it occurred to me to give it a shot. It wasn't on from an online/streaming perspective, my guess is because of All-Access and similar entities (I'm WAY too far away to hear the local feed).
They discussed this very topic last week after the Vikings game. A guy called into KFAN (Twin Cities All-Sports Channel), which has the Vikings radio broadcast rights, and he was an over the road truck driver, and he was mad as hell he couldn't get the Vikings game on IHeart Radio via KFAN from wherever it was he was at in the U.S.A. (assuming he's a Twin Cities resident or nearby and used to listening to KFAN).
KFAN DID have the Vikings game on locally and/or however far their signal will reach (they have feeds/Sister Stations in Mankato, Fargo and Duluth I believe), but due to NFL contractual issues, they had the Wild or Gophers or some Hunting/Fishing show on IHeart Radio at that time.
So I just want people to know there is always a chance you won't get to hear what you think you're going to hear by attempting to find a radio station online that you know full well broadcasts the event locally you're hoping to get. Follow the money.