u/Sihplak - originally from r/GenZhou
Revisionism is not simply adapting policies and changing approach. Rather, it is distorting Marxism resulting (intentionally or not) in anti-Communist goals or outcomes.

In Khrushchev’s case, it’s more of the specific ideological line which informs the reforms taken, rather than the reforms in and of themselves. We can look at Mao’s critique here. In other words, the reforms were contextualized in a manner that benefitted bourgeois interests rather than the proletariat.

Deng’s reforms did not fall into this category. Khrushchev was a revisionist because he eschewed the notion of class dictatorship as the nature of state power, while Deng was adamant about the proletariat maintaining state power. The reforms of Khrushchev acted as a means to degrade the level of proletarian development of the USSR and instead accept bourgeois notions of “peaceful coexistence” with Capitalist powers. Deng understood that, even if maintaining positive basic relations with Capitalist powers, there would always be a continued antagonism between them, hence the idea of “hiding one’s power” (to paraphrase) that he advocated for during China’s development under his leadership.

Khrushchev’s reforms have superficial similarity to Deng’s, but not essential similarity. Agrarian reform under Deng was not to denounce collective farming, since it remained in place in various areas, but rather, to follow the Marxist-Leninist line of dialectical materialism; much of China were still peasants and were in regions difficult to maintain such large-scale collective farms in. Thus, things like the getihu system and “contracting down to the household” were done, and weren’t simply for the purpose of decentralization or so-called “efficiency”, but rather, for the very purpose of serving the people. Wan Li’s argument in favor of “contracting down to the household”, for example, involved pointing out the fact that the peasants were having trouble getting just enough to eat due to the problems of over-centralized systems. (Screenshot from page 439 of Ezra Vogel’s biography of Deng Xiaoping) This can lead us to think to a portion from Maos critique of Khrushchev linked above:

Khrushchov has substituted “material incentive” for the socialist principle, “from each according to his ability, to each according to his work”. He has widened, and not narrowed, the gap between the incomes of a small minority and those of the workers, peasants and ordinary intellectuals.

When centralization and bureaucracy is not serving the people, then it objectively arises that it is not serving the Communist or Marxist line, and moreover, may be associated with some fundamental error in class analysis, such as in the case of trying to universally impose collective farming on disparate, non-proletarianized peasants, especially in mountainous areas and other areas difficult to maintain large farming systems on.

So, in short:

1. What matters are the objective consequences and theoretical basis in determining revisionist character. Those that distort, misrepresent, etc. Marxism are falling to revisionism. Such errors, opportunist attacks, etc. can be seen in ignoring or eschewing the issues of class struggle, establishing systems or institutions that aid bourgeois interests or intensify class divide, etc.

2. Khrushchev’s policies were to denounce Stalin, to deny the class nature of the state, to promote an idea of “peaceful coexistence” with antagonistic Capitalist powers, and to implement economic reforms which, while on a basic level helped improve small industry, on a systemic level had major problems such as not adequately maintaining price updates and economic liberalization without adequate state control or influence.

3. Deng’s reforms were never against the workers, but rather, premised fundamentally on the material conditions of the people. The decentralization policies allowed for small producers to become more prosperous as would those in their communities, helping with distribution of benefits to the people given the level of economic development in China. The development of private enterprises, further, were never in a context of them gaining political power, but rather, always being subjected to the central authority of the Communists, who maintained a consistent and popular line.

So, Deng was not revisionist since the basis and material outcomes of his reforms were fundamentally predicated upon a Marxist character; analysis of the material conditions of the people, ensuring the central authority of the Communists and proletariat over any private capital interests, maintaining total control of land by the CPC, etc. Khrushchev’s reforms, meanwhile, had a fundamentally erroneous position, which were, at best, not studied well enough in Marxism (if we’re generous to him and say he was a “Marxist”), or at worst, was an actual Capitalist roader.