You're missing the point of the parent. If CNN breaks it on Twitter, they COULD break it on cable immediately. They've done it many times when real news occurred. They COULD break the flooding in your area (and probably would) as soon as they learned of it. I'm guessing the actual lead time, if it's something as important as a major flood, is a matter of at most a minute or two.
Which means that all Twitter in this case did is bombard people with stupidity 30 minutes before cable TV did the same. That's not a value add. If anything, it's an extra 30 minutes before this stupid fact pushes something useful out of my brain. Because I avoid Twitter, I knew who won the Battle of Trafalgar for an extra half hour before cable ruined that.
If you wanted to give an example of Twitter being useful, you'd give one where some normal person (not a cable news network) broke a story that got big before the MSM even found out.