Iran is too much of a political hot potato for there to be much prospect of such a high profile military co-operation deal between China and Iran.
Although if the sales and marketing people at SAC are any good, they will be hinting like mad at Iranian interest in the project, especially to their arch nemesis the Saudis.
Even if the FC31 might not be enough to clinch Saudi funding on its own merits, the Saudis might still be willing to 'buy' the project if that means keeping the fighter and technology out of Iranian hands.
While all the recent big ticket UAV deals with SA, UAE and other Gulf countries have indeed significantly improved the chances of other major purchases of Chinese military hardware by those said same countries, we need to also remember that those are filthy rich countries that other vendors will be eying with great interest.
If SA and UAE came sniffing, I am sure Russia would make the PAKFA available (if they are not already proactively marketing it to them).
As such, it would be a mistake to assume that the FC31 is the 'logical choice because it is also the only choice'.
At the end of the day, it will mostly boil down to the capabilities and performance of the FC31 itself, as well as the credibility of SAC in delivering.
I think this is where SAC fell down hard with the PLAAF - their credibility is shot with the PLAAF after decades of over-promising and under-performing, especially the mess they made with the Flanker line.
My guess is that the PLAAF simply lost faith that they can delivery what they promised, and are not giving them money until they see real results rather that more of the same empty promises.
That was the primary reason for SAC to go it along in building the prototypes, to try and prove to the PLAAF that they can deliver.
Sadly for them, it seems the PLAAF assessment of their capabilities are better than their own, because the first flying prototype, while a significant feat, still fell short of promises and/or expectations, which is why the PLAAF continues to show zero interest and SAC itself is devoting resources towards building the improved MK2 version over clocking flight time hours with the existing prototype.
Unless SAC can break with a habit of a lifetime and actually pull a magic bunny out of the hat with the FC31 MK2, I think their best chance to an actual order for the FC31 lies from political plays rather than selling the bird purely on its own merits.
That is why I suggested they play up the Iranian angle to try and get the Saudis to pony up if only to block Iran.
The Saudis are certainly rich and unaccountable enough to be able to buy both the PAKFA and FC31, so I think it's a real possibility. Just not the near sure thing some others have almost implied.
