There is some truth to this for sure. Part of it depends on how seriously you take the word “planning.” Planning can mean “I’m planning to visit Las Vegas at some point in the future” or “We have plans to visit Las Vegas next month.” The verb is the same, the reality of the two are quite different. This is probably not even going to meet the bar set by the first, vague example. But let’s get into it a little anyway.

Khrushchev’s reforms were definitely not just about some short-term improvements that "derailed the Soviet Union from the Marxist path." Indeed, I think Khrushchev certainly would have understood them to be precisely the opposite. When seeing your question, I was reminded of a passage from Ronald Grigor Suny's The Soviet Experiment, a common textbook for Soviet history courses. I'll quote the relevant paragraph in full and then add some further comments.

In many ways Khrushchev was an idealistic Communist. At the Twenty-First Party Congress early in 1959 he announced that the USSR was entering a new stage of history, “the period of the full-scale building of communism,” a period in which state regulation of society would decrease ant h the role of public organizations, like the soviets, trade unions, komsomols, would increase. Communist morality, rather than state authority, would regulate the relations between people. Two years later his supporters drafted a new party program, the first since 1919. The new program declared that the USSR was no longer a dictatorship of the proletariat but now was to be considered “a state of the whole people.” The program made the bold claim that the Soviet Union would surpass the United States in per-capita output by 1971 an in other economic spheres by the 1980s. Under communism, which was now being build, the state would wither away, though not the party. (Ronald Grigor Suny, The Soviet Experiment, 407.)

Now, of course, this was a rather idealistic position and I don’t think that, ultimately, Khrushchev’s fate was tied to an ideological position. Rather, it was much more tied to the results of the policies. In the 1950s the Soviet economy, both in agriculture and industry, boomed. It grew even faster than the US economy in the same period – at a pretty staggering 7.1%/year (Suny, 409). However, by the end of the 50s and into the 60s things slowed down, and that was bad news for Khrushchev.

In response to the follow up question (and as an important part of the question anyway), destalinization is broadly speaking important to this story. Although destalinization explicitly took aim at Stalinist institutional excesses, the cult of personality, etc. it also served as a preamble to other reforms that Khrushchev wanted to push through. For example, in 1957 Khrushchev moved to decentralize economic decision making. (http://soviethistory.msu.edu/1956-2/the-anti-party-group/) Later, he proposed things as “radical” as term limits (which were ultimately rejected). All of this added up to Khrushchev coming off as a threat to those within the bureaucracy that had a lot to lose by Khrushchev’s reforms. His political reforms, combined with the fact that the economy of the early 1960s no longer provided Khrushchev with the shield it had in the 1950s, gave those who wanted to see him go the opening they needed.

So I don’t think it is really accurate to say that they pushed him out because he wanted to abolish the Soviet State. Brezhnev et al. did not see the Soviet system about to be imminently dismantled and abolished and step in to prevent it. Khrushchev just took no real action that resembled anything that kind of radical restructuring of society. Nonetheless, he certainly was a kind of true believer in communism and therefore believed that history was arcing in that direction. That ideology played a role in the policies that did, in fact, ultimately cause his downfall.

Related question: would this be tied to his policy of de-Stalinization?