SAC wouldn't have continued to invest in a second prototype if it didn't have some serious inquiries and some threshold to attain based on those inquiries..either from the Chinese air force or navy as well as from potential foreign customers..
But FOC in 2024 is a bit too long for exports, since many (at least) GCC nations might be able to get the US F-35 by that time or not far from it, still Egypt and other Arab countries like Morocco and Jordan might wait for it to be fully operational before purchasing it.. Pakistan on the other hand can join in the production and make a JV like the one with the JF-17, that is if it wants good numbers, a hundred or so.. the possibility is there since Pakistan's economy shows very good signs of progress and pronostics are most positive for a GDP growth of 7% by 2018..