I agree with your later points. However, this aircraft is actually massive in size. If we exclude Russia's high-speed interceptors or fighter-bombers, the J-XDS's dimensions and weight would surpass all fighter aircraft in history.It's not as huge as the J-36,that's why it apply single seat without back seat operator,and just like F-35,perhaps the avionics AI can help it fight with UCAVs,which different from another project.(China's aviation research institutions have always been at the forefront of Technology,even if the material conditions are backward, they are still catching up with the trend.There is no reason not to combine new concepts to the latest advanced project results.)
Therefore, I believe it's more likely that Shenyang Aircraft Corporation never intended to rely on a second pilot for drone operation from the design phase.