Authoritarians lack imagination and creativity.
They usually cannot imagine something completely new, they must "piggyback" off of something that already exists.
Because there has only really been Authoritarian Communism a la Russia, that's the only way authoritarians can think of what communism would be, since again, they lack imagination and creativity.
Seemed pretty clear to me. You link about art but OP not talking about making art. I think you just saw the word "creativity" and thought they meant art or something. They were more so talking about creating systems of governance than creating art.