China is building all these carriers without knowing what naval planes it will get. Eventually it will have to deal with the problem call "fit".
The current carriers are designed for the J-15 series though.
If the J-20 is turned into a naval fighter, it would almost certainly be for the catapult carriers, and China could make them slightly larger than the USN supercarriers to reap the benefits of having larger fighters.
There’s even indications for it as the 002 has been measured to be 41 meters wide, which is as wide as the Ford carrier, despite being China’s equivalent to the Kitty Hawk carrier which was significantly smaller.