Grand Prix format changed

I just looked at the Grand Prix Final schedule on the USFSA website, and it
looks like the skaters are no longer required to skate 2 long programs. When
did the ISU decide to change this -- with CoP system perhaps??

This probably makes more sense for the skaters so they don't have to train
two different long programs just for this event. But selfishly, I was
looking forward to seeing the different programs as I have purchased the
all-event tickets.