We don't know wether the PLAN requires the 076 to be able launch 5th gen fighters or not. However if the PLAN did have that requirement then I would say it is rediculous to deploy a STOVL fighter on a ship with catapults, especialy since a STOVL fighter has reduced load anyway so you might as well launch the aircraft with the reduced load using the shortened catapult.
What is the fully loaded weight of a GJ-11 drone anyway? A fully loaded GJ-11 is probably only 2-3 tonnes lighter than a J-35 with reduced fuel load & say 4 A2A missiles.
In the end I would say regarding the length of the catapults we have to wait and see how long they actually are and how many of them there are & wether they are all of the same length or not.