I know several friends who went to Cuba in the 1990's, and there was still a fair amount of steam running, both SG and some NG. Mal Tiempo NG was one line that was quite a show. In the late 90's and beyond the sugar market got bad and there was less and less operating steam there. I suspect the engines are still there, but doubt we will ever see the sort of concentration of steam operations like we saw in the 1990's.
One thing I found troubling was reports of fans going down there and paying money to crews for stuff like smoke, runbys, etc. Other fans would later go down, and crews expected bribes more often than not. Sorta too away the meaning of regular operations if you know what I mean. It got to be where the trains were operated more for tours and tourist fans than regular sugar cane seasonal runs.
I am sure we will learn more if relations improve. Lots of cool old 50's cars down there too.
Greg