China so far didn't purchase JF-17 for PLAAF or PLANAF , but that doesn't mean they would not in the future, especially when Chinese domestic engine WS-13 becomes available . After all, they have a lot of J-7s that need replacement .
How many J-7 (and Q-5) are actually left ?
My guess would be that only 400 to 500 J-7 and 100 to 200 Q-5 are still active.
I think that in the last years about 70 of these would have been replaced by J-10,J-11 and JH-7 variants each year, with J-10/J-11 variants replacing J-7 and JH-7A replacing Q-5.
Continuing like this would replace all 500 to 700 of these old planes in 7 to 10 years time.
If we assume that WS-13 is ready for serial production in 2 years, this would leave 350 to 550 planes to replace. If 20 JF-17 were produced each year for PLAAF in addition to the other planes, after 4 to 6 years of production there would be no really old planes to replace anymore
and the PLAAF would only have received ~100 JF-17.
Considering logistics and maintenance, I don't think PLAAF would want a fighter with a different engine in this small number.
But if the PLAAF stops procuring the JH-7 and uses newly built flankers not to replace J-7 but to replace strike aircraft and build up carrier wings, then replacing the remaining J-7 with J-10 alone might take too long and building ~200 JF-17 might make more sense.
I don't know what the start of regular production of J-20 might do to production rates of other airplanes. If it means that in the first years only a small number of J-20 would be produced instead of a big number of J-10, this might favor building JF-17s. On the other hand one can argue that instead of setting up a production line for JF-17s, resources would be better spend in setting up a production line for J-20s in addition to the existing production of J-10s.
In short, I don't think it makes sense for PLAAF to purchase a small number of J-17s, so I agree with Jeff Head that the remaining J-7 will most likely be replaced by J-10/J-11.