JF-17 will require another upgrade in 5 to 7 years just like upgrade from block2 to block3.The JF17 programme has reached full maturity and from now on, there will be only manufacturing and upgrades of planes and integration of new weapons to the platform. The design for Block III has been locked down, and there has not been any word of subsequent blocks.
No PAF official has mentioned or spoken about a Block IV for the JF17. The offial PAF narrative stops at Block III. PAF is moving onto Azm, what ever that means and it will be the core focus of their resources for the next decade.
Once we are done with the production of 50 block 3, we will move to block 4 production.