I think the F-16s, particularly the older ones are pretty heavily used. With current levels of constant high alert against the Indian border, I doubt airframe life will remain for a good chunk of them by 2030. Already by 2025 Pak will begin to have problems.
The airframe is not a simple aluminum alloy frame like the Mirages. There is extensive composite use and this makes it very difficult to keep them operational beyond a certain life span. If supply of parts runs dry, problems will be multiplied.
Even USAF is having very similar problems maintaining their F-15s and F-16s already and are being forced to procure new F-15s. Apparently cheaper and considerably less hassle than maintaining older F-15Cs.
Then there is replacement from accidents - 10 already lost. All aircraft don't age equally so you will have lemons to deal with. You will have problem aircraft that will need replacement by 2025.
There is one other option - lowering airframe hours by introducing a suitable LIFT. Perhaps that is what Pak is getting from Italy.