IRL Cuba became a de facto American colony, but it had its own (inefficient) army and the absence of US troops on the island made it possible for Castro to instigate his revolution. Also Batista used the Cuban army to gain power. No army = no Batista.
If it been a US territory the legal protection of the population would have been better = less corruption, less extreme oppression etc.
It wasn't in Puerto Rico until the 40s and 50s... and it was increased self-governance that ensured that.
Also, why should we assume the US would have had the political will to go through with the not inconsiderable bloodshed necessary to pacify Cuba without granting nominal independence?
I am assuming that any attempt to rule Cuba as an ordinary territory after 1898 leads to an outcome much like real life in the not-so-very-long run. The details would vary, of course.
