That is wholly incorrect.
Neozapatismo is also type Marxism, and is not Marxist-Leninist. They are a non-white manner of organizing a communist society. (They will claim they are “None of the above”, rightfully so, however, analysis will show it’s a Marxist-based ideology and system, with some Anarchist ideology too).
Leninism is in fact, a departure from Marxism, as it fully drops the “scientific” part of the entire ideology. In fact, Leninism, arguably, isn’t even socialist, since it merely gives us new oligarchs in lieu of the old oligarchs.
It could have been an experiment in Marxism, and I’d say it was an experiment in Marxism. However, it is certainly a failed experiment. The Neozapatistas have persisted for 30 years now, for example, and are so far doing much better than the Soviet Union did as a liberatory movement. Same with Maoism, which started off good, but made the same mistakes the Soviets did, and now we just have another capitalist state.
Ok, so show us a Marxist-Leninist society, that hasn’t turned into back into an oligarchy.
I’ll wait.