I've noticed this a few times now when searching for DL flight availability for upcoming trips a few days out (checking upgrade probability, etc). It will go from F/J 9 to some other number. Just checked it now for my Monday flight SFO-JFK, and the previous J9 dropped to J4. When I checked the seat map it still only shows 1 person in J. I also noticed every other flight had available fares maxing out at 4 both in F/J and in economy.

Is this something on DL end or EF? What's going on here? I can still go to the DL website and search for 9 seats and it does come back with available fares.