We'll have to wait and see.
Rationally speaking, for the PAF, the F-16 Block-72 is the most plausible outcome as an interim until Project Azm.
It's the same airframe, engine, etc. as the Block-52, but with an AESA radar and new avionics. So for the most part, the Block-72 would re-use the PAF's existing logistics/maintenance infrastructure.
Moreover, thanks to Bahrain, Morocco, Slovakia, etc, the F-16 will also remain in production for a while, so the PAF has some time to decide (or to put it more accurately, come up with the money).
For around $5 bn you can probably get 18 new Block-72s plus 60-76 update kits for the existing F-16 fleet; build out a fleet of nearly 100 AESA radar-equipped F-16s.
However, that's a colossal ask, we are talking about giving national funds over to the US; so unless there's aid or subsidies, it's a tough ask. Remember, the PAF and PA both walked away from their Vipers over the suspension of CSF/FMF. On the other hand, if the US extends an EXIM loan, that might change things.