You can make a strong case that Cuba is the only remaining genuine communist state in the world today. North Korea is a monarchy, obsessed with nuclear weapons and self-sufficiency, not world revolution and the plight of workers; China and Vietnam are run by the Communist Party, but have largely capitalist economies. Who else is there?
This obviously suggests that the tide of history is running strongly against communism in Cuba. It does not, however, indicate that the Communist Party will lose its grip on the island any time soon. Without the charisma of Fidel Castro as a backstop, the party will gravitate towards the Chinese model in order to survive. It will have no choice.