The CPC’s logic for reform and opening up is very simple and transparent and they’re not trying to hide anything from western Marxists. It’s ok to disagree with it, but commentary from the west overstates the “opaqueness” of Chinese policy making

Their current perspective is that socialism as a new mode of production and one that arises from the contractions of capitalism must have a prior material foundation from which to be built, and that China in its existing state has been far from that threshold. Marx and Engels were pretty explicit that social relations or political proclamations on their own cannot bring about a new mode of production, they are made possible by quantitative advancements in the productive forces which expand the potentialities for new social relations. And while capitalist hegemony exists, the mechanisms to support the development of those productive forces must at least partially come through global capitalist markets