In the decades after the second world war, a number of communist semi- and crypto-communist states changed their names on the coin, leaving the design unaffected. As one example, the (frozen date) 1953/55 series of Yugoslavia is in the name of the Federal People's Republic of Yugoslavia, while the 1963 series is in the name of the Socialist Federal Republic of Yugoslavia. There are examples from other countries.
The change is significant, as the US government swallowed the propaganda that communist is socialist. Even today, in American mythology socialist equates communist, which is bovine excrement. I am not aware of the actual reason for the change. My preferred theory is that it has to do with a Marxist dogma that, as communism took over, the state would wither away, worker's brotherhood would arrange everything, money would disappear and a worker's paradise would ensue. See
this post, paras 10 to 14.
Peter