I could be wrong because I remember most of this from school. I don’t think we’ll ever get into Huang-Ti’s tomb, if you’re referring to that 黄帝 where 黄 means yellow. He’s sort of a legendary proto-ancestor and while he has a mausoleum, it’s more like a shrine of where he approximately left the world where offerings to him have been made. Some people don’t even think his remains are there because he ascended (lol). We say we are his descendants, 炎黄子孙, children of the Yellow Emperor and the Celestial Farmer, 炎帝. They are mythical figures. The tomb which is better known with the terracotta warriors belong to Qin Shi Huang, who united China. Is the government hell-bent on not letting people in because of the shock of finding an Aryan king? Maybe. The excuse for now is the huge amount of mercury in the tomb, known as liquid silver, which was thought to be a possible elixir of life.