You're completely correct but, I think, looking at the situation the wrong way.
The entire point of the Marxist Dialectic is the ideology evolving to match its material conditions. There is no such thing as "Vanilla" Marxism or Marxism-Leninism, because Marxism includes Dialectic evolution. Maoism is Marxism. Trotskyism is Marxism. Marxism-Leninism is Marxism. Socialism with Chinese Characteristics is Marxism.
This is why you should be suspicious of anyone who identifies with a sub-tendency, especial "Hoxhaists".