I once paraphrased this idea: "Let's help right-wing anti-Communist parties win elections in the West, get NATO and the western arms build-up started earlier, make the unification of the western zones in Germany into a remilitarized capitalist republic happen even earlier than in OTL (and the West German state will now be able to claim to dissatisfied east Germans "We are the only independent German state!"), cause unnecessary resentment even among those east Europeans who are sympathetic to Communism, deal a serious blow to the West European Communist Parties, harm Communism's potential of appealing to nationalist sentiment in the Third World, and lose several seats in the UN. And gain nothing in return, since Soviet military and police presence would be enough to keep the "people's democracies" loyal in any event. Hey, that makes sense..."
There is just no advantage to this for the USSR. Absolutely everything Stalin wants in the "people's democracies" from purge trials to military and economic integration of the bloc, can be (and was) accomplished without this crazy idea.
In any event, Stalin was actually less anxious to expand the borders of the USSR than Lenin had been. In 1920 when it seemed like the Red Army was about to being Communism to Poland amd Germany, Stalin insisted that even in that event, those nations must remain independent: "I said [to Lenin] - and this is all preserved in the archives of the Central Committee – that that would not work. If you think the nationalities of former Russia will stay in a framework of federalisation – that is understandable enough, but if you think that Germany will at some point come to you to join a federation with the same rights as Ukraine – you are mistaken. If you think that even Poland, which has taken the form of a bourgeois state with all its attributes, will enter into the composition of a union with the same rights as Ukraine – you are mistaken. That is what I said then. And comrade Lenin sent out a long letter - that is chauvinism, nationalism, we need a centralized world economy, run from a single organ."
https://www.alternatehistory.com/forum/threads/if-bolesheviks-conquered-poland.407915/#post-14031591
Stalin was consistent on this. Note what he said in 1930:
"Lenin never said that national differences must disappear and that national languages must merge into one common language within the borders of a
single state
before the victory of socialism
on a world scale. On the contrary, Lenin said something that was the very opposite of this, namely, that "national and state
differences among peoples and countries ... . will continue to exist
for a very, very long time even
after the dictatorship of the proletariat has been established on a
world scale" (Original Comment: JVS: My italics) (Vol. XXV, p. 227). How can anyone refer to Lenin and forget about this fundamental statement of his?"
https://www.marxists.org/reference/archive/stalin/works/1930/aug/27.htm
Observe that he is quoting Lenin to the effect that national
and state differences among peoples will persist long after the word-wide establishment of the dictatorship of the proletariat (and that last event had not remotely come about by the late 1940's anyway). To try to squeeze all the "peoples' democracies" into the Soviet Union would be a flagrant violation of this. (As I noted, Stalin was in fact more consistent on this than Lenin was, as their 1920 disagreement on Poland shows.)
The Baltics were a special case because they had been part of the Russian Empire. Stalin wanted to incorporate into the USSR the territories that had been part of the Russian Empire--and did not even annex all of those (Poland and Finland). But I just don't see any evidence that he even considered the idea for eastern Europe in general (indeed when Gottwald allegedly once suggested it for Czechoslovakia, Stalin summarily rejected the idea [1]) and I don't see any reason for him to do so.
[1] Admittedly, Gottwald was drunk at the time, if one can believe Khrushchev:
"In 1948 Klement Gottwald was vacationing in the Crimea with Stalin. Stalin called me up and said: “Gottwald is here. Come join us.” The next day I flew there. We gathered at Stalin's place for dinner. Gottwald had drunk a great deal (he had that weakness) and began to say, "Comrade Stalin, why are your people stealing our patents? Just tell us and we'll give them to you for nothing. When your people steal them and we see it, we feel offended. We can give you more than just patents. Take us in as part of the Soviet Union. We'd be happy to join the Soviet Union and then everything we have will be common property.” Stalin refused to take them in, and he got angry over the thieving. But that was only in words, because we continued to steal, sometimes just out of old habit, like the gypsy who was asked: “If you were king, what would you do?” He answered: “I'd steal me a herd of horses and disappear."..."
https://books.google.com/books?id=uv1zv4FZhFUC&pg=PT242
This incident, if one can take it seriously, fits a pattern: most proposals to incorporate satellites into the USSR came from the satellites themselves and were rejected by the USSR. E.g., Mongolia
https://www.alternatehistory.com/forum/threads/ahc-mongolian-ssr.352879/#post-10705074 and Bulgaria (though I doubt Zhivkov's alleged offer was meant seriously).
https://www.alternatehistory.com/fo...-eastern-bloc-into-ssrs.413844/#post-14546885