In a former lecture, Yang Wei (J-20's Chief Designer) said, J-20 is not going to equip TVC engines. It's designed for OODA 2.0 instead of OODA 1.0, no need to pursue dogfight capabilities.
Here's the lecture. (From 20:12)
Also at 32:42, Yang said, J-20 is less stealth than F-22 (with 2D TVC) from the rear, due to design trade-off. Our engines are weaker than American's, so we need trade-off from the very beginning.
At 34:51, he said, only US and China have directional data link tech.
