Illinois regs
don't mention anything about lighted nocks. Though it does mention electronic tracking devices are illegal.
"Electronic
tracking systems utilizing radio telemetry are illegal."
Maybe your guide misunderstood this reg and assumed it also pertained to lighted nocks. I know several people here in Illinois who use them.
I had one person tell me that the best thing I could do if I had a question about something was to call the conservation police and ask them.