Infrastructure building, including housing, was a major part of the Chinese economy. That part of the economy collapsed, which is causing China to try to transition to other industries to drive economic growth.

It is possible that the IMF is worried about the collapse of a Chinese industry, but it seems like China is trying to focus more on the effects of a collapse on the asset class given that said asset class is the main retirement savings in the country and the main driver of local government spending. China has also taken internal steps try to limit infrastructure spending in the last few years, so they may not be worried about development companies collapsing as long as their collapse doesn't spread to the overall economy.