I don't know...
In chapter 3 of The Road to Serfdom, entitled "Individualism and Collectivism," Hayek endeavored to define and describe collectivism, with the specific purpose of clarifying the similarities and differences between Communism and Naziism (both being collectivist ideologies). Roughly speaking, Hayek defined collectivism as centrally planned economy.
I don't think Hayek used the word "statist," but my layman's interpretation is that statism would be the specific form of collectivism in which the centrally planned economy is planned by the state. Non-statist forms of collectivism might include non-state sponsored communes, and maybe the financial management of a nuclear family.
This is my understanding, but I'd be happy to be corrected by someone who knows better.
I wouldn’t even call them statists, more like anarchists since those guys have absolutely NO respect for the law at all. Not to mention Marx specifically indicated that not only would class distinctions fade away, but also the state, meaning he wanted lawlessness, literal lawlessness akin to the French Revolution. As did Lenin, he made sure to make law and order illegal in the Soviet Union, make it literally lawless (just read Gary Saul Morson’s Leninthink).
And let’s not forget Sartre advocated for all of the above and specifically viewed himself as an anarchist. As did most of the left during that time and during the Spanish Civil War, siding with the Spanish Republicans who were, among other things, anarcho-syndicalists. And that’s not even getting into their founding fathers, the French Enlightenment, who wanted God removed and any and all law and order. Read Barruel’s Jacobin Memoirs.