I don't understand why they focus on IL and not all states. I have a therapist friend who says all states have a mandatory reporting obligation.
Here is a link and you can go to your state to see what or who is required to report. I typed in a few states and they all had the following- https://mandatedreporter.com/blog/how-many-states-have-mandated-reporting-laws/
- Members of the clergy or religious order, including brothers, ministers, monks, nuns, priests, rabbis, or sisters