If not for political reasons, I'd think JF-17 would also be a good upgrade/replacement candidate for users of F-16A/B and F-5s.
I think the F-16's will actually turn out to be a competitor to the JF-17 market. In the coming years, with F-35's rolling out of assembly lines, there will be a surplus of used F-16's entering the resale market. The prices for used F-16's will be very competitive. In case of Singapore, they "donated" (free!) their used F-16A/B to Thailand in exchange for using their bases for training.
See the title of this article "Saab offers Gripens at used F-16 price":
I think the title itself says it all.