That just goes to show you how your knowledge of current events flavors your ideas. I say this because I was about 12 when the song came out and I thought it was joking, because "everyone knew" how bad it was in the USSR at that time.
I always assumed it was just The Beatles being nice, and drumming up a huge market with some kind words and a fun song. But yes, we all knew it was not saying that Moscow girls and Miami Beach girls were partying and enjoying life and love with the same fervor.