A380 doesn't fit into PIA's current strategy and would have heavy competition from A350 and B773/787 for several reasons.
First of all A380 is a heavyload ultrarange (16.000km+) super widebody with a 3-class capacity of 555 passengers in a typical layout. The aircraft could successfully be introduced on heavy density point-to-point trunkroutes like ISB-LHR/LGW, ISB-JFK/EWR, ISB-IAH or ISB-YYZ. But for any other route the aircraft will result in overcapacity making it less profitable in shoulder or low season.
Advantage of other smaller long range designs like the A350, B773 and the B787 dreamliner is the lower( seating) capacity making it easier for small airlines like PIA to maintain loadfactor in the range of 85-95% throughout the year.
A380 needs specific infrastructure and grounhdhandling facilities whereas the A350, B773/787 can operate from Karachi, Lahore, Islamabad, Sialkot, Multan and Peshawar. All these aircrafts have the same benefits as the A380, the only difference is the lower capacity making them less vulnerable to market trends.