Well all the ground handling equipment has now arrived at LBA so to be able to handle the B772 if and when they do decide to start op's with it. I’ve been told this could happen once PIA take delivery of 2x B773 which are been leased on 5 years deal later this year. Which in turn will release a B772’s to operate the LBA-ISB route.
Regarding the drop in pax figures on the route recently. I think you'll find this tends happen every year around this time due to the religious festivals of Ramadan, Eid & Hajj.