It says in the opening paragraph "tighter currency controls by the Chinese government". As with most financial articles there is no discussion of the relative magnitude of the effects at play. Financial journalists are perfectly happy to ignore the elephants in the room and report a laundry list of tiny effects that might have had an impact and then devote 1 line to whatever causes 80% of the change observed.

Fleeing implies they have a choice and are choosing to leave because of poor prospects in US housing. That might be true. But the choice might be involuntary or be due to sharply rising prospects in China or elsewhere. If China those capital controls are significant, maybe a better title is "Chinese purchasers dragged away from US housing kicking, screaming and cursing their own government". That is a possible interpretation based on what is included in the article.