Isn't the World Described by the Marxist Historical Dialectic an Implicitly Teleological One?

It was a Marxist-Leninist article of faith that the totalitarian state (indeed, the State itself) would pass away once its goals were achieved and the proletariat was capable of direct rule. The totalitarian "dictatorship on behalf of the proletariat" was a phase on the way to true communism, which has never been achieved. True communism was to be regarded as "the fulfillment of history." True communism is basically sugarcandy mountain, akin to the christian heaven - but conveniently located here on earth!

In the future, of course, where one can never get at it.

One thing I never understood: Marxism dictates that any status quo ("thesis") automatically generates its own antithesis, and that the two inevitably come into conflict, clash, struggle, merge into synthesis - which in turn is a thesis of its own, which in turn will generate its own antithesis.

So I've always wondered: if once true communism were achieved, what antithesis would it generate? Or would true communism be somehow stable - somehow inexplicably exempt from the inexorable laws of the historical dialectic? An uncausing effect, to answer once and for all the uncaused cause?