Did we see huge amounts of pilots training ski jump launches when Type 001 and 002 were to come into service? Not that I can remember. We could not see the aircraft show up in large numbers with new batches just before Type 002 came out either. In fact we wondered when the heck they would produce the aircraft for the 002 carrier.
This time we have seen pictures of the catapult variants of the J-15 and J-35 at the land based test facilities. Supposedly prototypes, but they look to be in advanced stage of completion. With all the delays of testing it would not be unreasonable if they spend like two years testing the carrier before it goes into service.
Before it enters service they do not need either a lot of aircraft or a lot of pilots.
And yes, with all the pilots they need to train, at this point they would be better served if they had a dedicated trainer aircraft which was capable of catapult launch.