Is it possible to retrofit catapults after removing the ramp and re-fitting a flat deck to these carriers? Because China now has developed EMALS as well as catapult-capable aircraft. It would be a pain to have different aircraft for different carriers. Also, I think KJ-600 would not be able to operate from these carriers either.
We already know that J-15T can operate off the STOBAR carriers. We can also expect J-35 to do this, given the mockup on Liaoning last year. Considering the age of Liaoning and the mentioned flexibility of existing aircraft its arguably not worthwile pursuing dramatic modifications, even if it were in any way feasible. Any overhaul also takes those carriers out of service, and as we saw with Liaoning, even mild updates still take many months to complete.
CV-16/17 will probably continue training crews for some time, while Fujian comes online. To say nothing of any notional new carriers, which at this stage are arguably about a decade away from meaningful service. By the time a substantial CATOBAR capability is available, Liaoning will have reached end of life, and Shandong is probably not that far behind.