There's a good chance that they ask the bell ringer to arrive 15 minutes early to shake hands and iron out the bell ringing rules (don't ring early or late, make sure everybody is clapping, don't use "the finger" to ring the bell)
You all need to read and not react. The PR says, "The ceremony will begin at approximately 3:45 p.m. Eastern Time and..." That means there is a sequence of events that leads to the closing.