Of course it’s China so there’s always a price eventually. I suspect Beijing’s goal here is additional influence within Cuba, and I don’t see any reason why Cuba would have any objection. A few boatloads of rice gets you a LOT of good will in a starving country.

With a collossal oppressive empire like the US at their doorstep demanding full submission, the Cubans are likely very happy to have any alternative. At least Chinese agreements usually benefit both sides instead of “surrender your country or we will kidnap your president”.