Unless meant for some kind of next-gen trainer aircraft/light fighter for export (low viability) and/or loyal wingman UCAVs (more realistic) - Developing single-engine 5th-gen fighters today makes little to zero sense for China, especially with the unique operational requirements which have been tailored for the PLAAF and PLAN in mind.
By now, the F-35's infamous debacle with its sole F135 powerplant should have been a very obvious warning for all WRT designing the proper powerplant for future fighter jets, which are only going to be more energy-thirsty and power-hungry than ever before.
Plus, for carrier-based fighters, having two engines is always better than only one.
This post and a couple others in the Ask Anything Thread (Air Force) have explained the topic very well.