That's different because it was a school. They had a legal obligation to report it. The Blackhawks didn't. They won't be getting any jail time.
I'm not so sure. Three individuals were charged in the Sandusky case, not the school itself. "On November 1, 2012, Pennsylvania Attorney General Linda Kelly announced that Spanier had been indicted for grand jury perjury, obstruction of justice, child endangerment, failure to report child abuse and conspiracy in connection with the scandal. Curley and Schultz were also indicted for these charges in a superseding indictment." Most all states have laws about making the reporting of a child abuse a legal requirement. Its unclear how much the State of Illinois has such laws (they should) or how much those sort of laws apply to a 20 year old, but this isn't a distinction between "employer and school". The laws apply to individuals. Schools may have additional reporting requirements but its State by State.
Its possible they might not be getting any jail time, but they should. Their inaction lead directly to additional victims being assaulted. When the victim is a child, every state punishes the person who withheld the knowledge. That the victim in this case is an adult changes little, morally/ethically speaking. The point is if you know someone is committing this sort of crime and you do nothing, there should be consequences.