The JF-17 will soldier on as a supporting point-defence or short-area fighter (taking on the roles traditionally given to the F-7P/PGs).
The twin-engine NGFA (J-31 or KAAN) will gradually phase the F-16s out. Until then, however, the F-16s and J-10CEs will form the PAF's offensive edge.
IMO...gradually...the NGFA will assume the offensive role (with UCAVs), while the J-10CE will work as an area-wide or large-area multirole fighter.
Overall, the PAF will likely start valuing larger longer-ranged fighters more than JF-17-type short-range ones. As guided rockets and TBMs become a go-to strike weapon for armies (both Pakistan Army and Indian Army), stationing fighters as close to the border is becoming increasingly untenable.
Hence, the value of the JF-17 is diminishing due to the rise of drones, TBMs, loitering munitions, etc, that either threaten it, or can take up some of its roles (esp., strike roles). Moreover, a good air defence system with capable SAMs can help a lot with the anti-air/intercept mission (see Ukraine).
Don't get me wrong; the JF-17 is still valuable to the PAF, but is it valuable enough to warrant additional units? It's starting to seem that the PAF itself doesn't think so (hence the Block-3 cuts); IMO, the orders meant for Block-3 will go to additional J-10CEs.