The J-10A already had helmet mounted missile cuing developed back in the 1990s and worked on the 1980s. The Russian 4th gen fighters first came out with these for the Archer missile although those cuing systems were naturally more limited than the J-10A's from the 2000s. Missile cuing is nothing new in fact it's Cold War era technology. The F-35's HMD goes far above and incorporate features mentioned. What the J-20's HMD includes is a mystery but all the nodes and cameras on the rear probably give us some hints. Missile cuing though is pretty much guaranteed since the 20 year old J-10 has it.