The Russians' usage of the term antifascist certainly didn't age well, but it's worth noting that "fascists" is how all people in the world referred to certain Germans and Italians for a period of 25 years all up until 1945 (and the affected folks didn't mind that - in fact, the term was invented in Italy in 1915 and then adopted by Mussolini in 1918 and by Hitler in 1923 [0]). So for Russians to refer to Germans who didn't join them as fascists is just a continuation of how the term had been used for a long time.
By 1961, it was definitely unfair to continue using the term in its original meaning, and at this point it was certainly the Russian government pushing their agenda a lot more strongly than the general population would have on its own. But it's not like everyone was strictly opposed to it either - the horrors of the war had created in Eastern Europe such deep resentment towards Germany that it would take a lot more than 16 years to get over that. In fact, my grandpa lived until the 90s and still called every German a fascist.