Provided USA provides itI am pretty sure that PAF will once again try to communicate with US for MLU's kit and additional New F-16 most likely F-16's, a similar deal of 18 units can be reached with delivery would take up to 2-4 years while the JF-block III fills the gap in both Quantity and with decent Quality. Honestly, I'd be surprised if PAF actually buys J-10CE now when JF- block 3 are ready to be integrated by the end of this year, and if they do then I am but forced to believe that PAF has/might send a list of upgrades and changes (Electronics) to the Chinese before finalizing for XYZ numbers of the fighters.
Which is big no.
Usa will not provide pakistan with aim9x and aim120D which will effectively make the f16 toothless in air to air role and waste of finances to be honest(unless subsidizid or used)
They are already toothless in air to ground role due to lack of stand off weapons, anti radiation weapons and antiship weapons
In 2004 USA agreed because the indian relationships were still not as strong, pakistan was vital for antiterrorism push, and there wasnt alot of negative press around f16s yet.
Pakistan had also approached europe for weapons who were agreeable to sell at that time as india hadnt lured them in their weapons program yet.
Its 20 years later and things have changed ...