The goal wouldn't be returning to the USSR but returning to socialism.
Yea that would be the challenge in using nostalgia of the past. That being said I think it has some use in agitation, but it's more important to follow class dynamics and unify people based on class.
I also missed that the question was specific to Eastern Europe, so idk how strongly the Soviet Union affects the culture
There is a difference between revering it and using it as an example to learn from. Lenin was objective when it came to analyzing and learning from the Paris Commune. He may have had warm feelings towards it but his argument in state and revolution was to learn from it rather than try to acheive exactly as it did.