I suspect they will build a second conventional carrier after they trialled 003, works out the kinks etc and gain 5-6 years of experience operating CATOBAR and will probably start building 004 (nuclear) a year after the 2nd conventional CATOBAR. This is inline with PLA's “小步快跑 快速迭代” (small steps, fast iterations) tactics. Instead of long development to come out with a final, mass produced model. We've seen it on LiaoNing and Shandong. 052C->052D->052DL. J10A-J10B-J10C, ZTZ-99->99A etc. They would want to field something in the transitional period, something the troops can use to gain experience and provide feedbacks.
PLAN's ultimate goal is to somehow match USN's carrier capability, blue water nuclear carrier task force, so i predict it will be improved 004 that will be finalised (定型)and mass produced like the Ford class.