This is quite right as PAF has started its own project of developing stealthy fighter, but it still need a partnership. As we all know PAF has shown deep interets in J20, so some CJDBY source is deducing it that the partner will be CAC.
And I strongly believe FC31 will get on board, modified with more robust engine to meet Navy's super cruise requirement.
It's no surprise if CAC can develop a customer single engine design 5th gen fighter based on WS10X or WS15. As India's 5th gen project is got stuck now, PAF has enough time to wait CAC and join the development together.
All these will be done under the table like JF17 project.
The specification is like can carry four PL15 in the weapon bay or Six SD10A. It might not need to make supercruise, but need very good stealthy features.
Good Stealthy feature with top notch AESA is way important than Supercruise ability. Fighter like J20 is kinda of overkill to most of the fighter on this planet, excluding F22.
When I'm looking for a partnership with someone in developing certain projects, I will choose someone had long term cooperation relationship with me and never default during cooperation. It's CAC for sure, can't excluding Turkey in the future.
A strong PAF fit in China's interests.