the big difference between J10 and J16 is that J10 can be exported, so it makes sense to open another line for it while Chengdu reorient to J20. with J10C being a top notch 3/3.5gen fighter, I can see Pakistan acquiring more of them in the future, and other countries too potentially. but the chance of J16 being available for export is very low, for a variety of reasons, and I don't see its production continuing for long enough into the future to justify opening new production lines. my guess is shenyang will produce J16 at its current rate for a while, then sustain a low rate of production for much longer as it focuses on J35.