Basically, if you want to be rich, Cuba is a terrible place to be. But if you have to be poor, Cuba is better than the alternatives, possibly including the US. Cuba is #50 on the UN Human Development Report, out of ~200 countries. It's no paradise, but neither is it a failure.
As to the question, it'll never happen. The revolution is forever.
"This Reich will last a thousand years!"
"Segregation today, segregation tomorrow, segregation forever!"
"We will bury you."
"Let them eat cake."
...
Cuba would be well-placed to shift into a social democracy now that communism has failed.
We have a winner.
The people are bright and the majority of Cubans don't want the system gone, they just want it changed to work a bit better - which wouldn't really be particularly hard.
The Cubans have always voted against communism, with their feet.
As mentioned, Cuba's social systems are rather good even by world standards, so if the country backs off on the Marxist-Leninist stuff it would probably be a decent place to get into business because of the bright people and smart government.
Considering that much of the world is populated by countries like Lesotho, Haiti, and Nepal, there's really no surprise in it at all.
Dictatorships generally survive longest in places with racial or social problems or where the population either by reality or by choice isn't very well educated. Neither is the case in Cuba.
That's because all independent thought is suppressed by the state.
Remember people what happened when the Soviet Union collapsed, Gangster Capitalism filled the void, it is only now that central authority is being slowly reasserted.
Putin has done a magnificent job, hasn't he?
Conclusion: In almost every case when a socialist nation becomes capitalist, some things which are better preserved are lost..
Like the Stasi, the Securitate, the KGB, the AVO, the STB...