to give context: remigration is a slogan held by far right parties in Germany with ties to neo-nazi movements. currently there are discussions to ban the most prominent, the AfD. remigration is most likely not a belief held by the majority of people living in Germany.
"During USSR" as you say, first wave of Russian immigration settled in West Berlin in 1920s running away from Russian revolution, so you probably did not mean that period of time. During occupation of Germany by Allies, both NATO and Warsaw Pact maintained significant military presence in Germany, but in 1990 Soviets have left (feel free to check it yourself in Karlshorst), Americans stayed. There was no migration of civilian Russians to Germany at that time, but DDR welcomed workers from other countries like Vietnam. Speaking of today, you can look at statistics on citizenship of Berlin residents: there you will find that, for example, more Indians than Russians are currently living in Berlin. And of course more Ukrainians.