PAF will acquire J-10 B, C or D whatever it is called with indigenous engine. It is just matter of time. There is many reasons for it. One main reason is PAF F-16s are again in trouble water as history is repeating itself, not sure if spare parts will have continuous supply from USA. Also the number of F-16 PAF planned has not full filled and there is very bleak or almost no chance that PAF can acquire more. Previously PAF was hesitant due to engine choke problem of AL-31F. Also it do not want to be hostage or take risks of single Russian source for all of its engines supply. So J-10 with indigenous chinese engine are second bests what PAF can acquire or afford for the time being.
That would be like a country buying an F-15 and then buying a Su-35. Why would anyone want another line of fourth gen fighters. When they could upgrade JF-17 to meet most of the requirements. What does J-10 offer that is so much more than JF-17 and F-16? Rather than investing all that money into yet another (third) single engined fourth gen platform, why not invest that money into FC-31. That would be good for SAC and China too.