It was an adherance to more traditional Marxist economics than under the Gang of Four. Marxists don’t believe you can develop the productive forces to the level where public ownership is better through fiat, or by decree. If you go back and read Marx and Engels, and even Lenin, they make it clear that they believed even in developed Capitalist economies, only the large firms should be nationalized, while the small firms should be allowed to naturally develop, perhaps with a bit of a push.
Anarchists don’t want a fully publicly owned and planned global republic, Marxists do. Anarchists want networks of decentralized communes, Marxists do not.
The “state” for Marxists is the oppressive elements of society that make up class distinctions, such as private property rights and the current police structure, whereas for Anarchists its usually seen as a form of hierarchy entrenched with violence.
Chiefly, a decentralized network of communed does not get rid of class, but entrenches petite bourgeois class structures where each commune owns only what is within its commune, whereas Marxists want to abolish class by making all property equally owned by all in a highly developed and complex economy.