There is rumor of a Block-2+ variant, initially raised by Azerbaijan purchase speculation but now it is for PAF as well.
Since Block-3 will have a different engine and major internal changes which wont be feasible for upgrading on previous model. Block-2+ would be a block-2 JF-17 with an air cooled AESA radar which China claims is a bolt to bolt replacement as well as other electronic and minor upgrades.
The power consumption of the radar is low enough for existing system but with greatly enhanced capability.
For AA combat paired with updated, PL-10, SD-10s and PL-15s these will be able to stand their ground against even Rafaels. Also will be able to guide 4 missiles at a time so we might see Block-2+ with multi missile rails.
So even the existing fleet will pack more punch.