So, do you think the quotes from people running the system who say that is not the case are lying for some reason? Or do you think you know more about how their system works than they do?
The question still stands. Why interrupt the road traffic if there are no pedestrians waiting? It's possible to answer that "for flow control" but I'd warrant that's not an effective proposition for the majority of junctions.
I didn't see this specific question addressed in the OP so it's quite possible it was simply glossed over to provide a simplified answer or the reporter worked around it to make it easier to express the sequence.
