Well he had a different "boss" back then, LOL!
Stalin wanted a national anthem in the closing days of World War II because the Communist “Internationale” was embarrassing and reflected a country in revolution.
It wasn’t fitting for a nation-state and needed to be changed.
The post-war Soviet Union adopted conventional nomenclature for the government as well as recognizing it was part of a world in which it was no longer isolated.
Pretty much the same reason the Germans changed their anthem in the aftermath of World War II.