The meeting will also include US business leaders and Yellen will then also meet with Chinese premier, Li Qiang, after. The official says that Yellen will address “unfair practices” by China and that the US has always made it clear that it does not support a decoupling between the two major economies.
Liu He might be retired but he is still one of Xi Jinping’s most trusted confidant, especially on US-related matters. That would explain the meeting between the two. We’ll see if there will be any concrete developments from all this (I doubt it) or this will be yet another case of putting on a show just for the optics (which I would expect).