It's a little unclear, but I think it's another "1984 is a great instruction manual" joke.

Nineteen Eighty Four is more meant to be against all forms of totalitarianism regardless of political ideology; the Party's actual political leanings are kept deliberately ambiguous and their goals are simply to retain their absolute power. The naming of their ideology as "Ingsoc" also compounds this by the fact that the Party for all intents and purposes perverts the name of socialism in exactly the same way that both the Nazi Party in Germany (who intentionally gave themselves the misleading name of "National Socialists" to manipulate the German working class into supporting their fascist end goals) and the Communist Party in the Soviet Union did.