Strange 31R APPROACH ON SEPT 1

I was at the US Open on Sept 1. The sky was very clear. I noticed an aircraft heading over the stadium about at a 160 degree heading. It was about alt. 16,000. I had a feeling it was a Kennedy inbound. My hunch was right but it made an unusual approach. It turned-out to be QTR 83, a B777. After Lendy, it continued north of the LGA VOR and continued passing near Franklin Square, Brentwood, Central Islip. East of Bay Shore it finally turned south and passed Moses Causeway and then vectored in to the 31R Approach. Usually, the 31R Approaches from Lendy pass by Brooklyn over the Atlantic and make a loop until joining the 31R LOC. AZA 60U also made the exact same approach. Was this unusual approach used for separation? How often is it used? I also saw the Direct TV airship hovering over the Stadium all afternoon.