So the shooter somehow knew that he had enrolled at the school (not only the fact that he had enrolled, but also the time and location of his classes), but did not know that he was appearing on a highly-rated national TV show (and thus would not be attending the school)? Seems highly unlikely.
If we were to look back through history and examine scenario after scenario, they would often seem totally unbelievable if written into a work of fiction. Keep your ears pricked and nose up. I'm betting there is more to come.
Im just the messenger.