I'm surrounded by Haitians down here, and have never heard of a Banana Mango, or anything similar named. the favorite mango of the Haitians is by far the Madam Frances, ( French Lady ) sometimes called Francine here is the Madam Frances with the so called black speckle banana spots.
another Haitian Mango variety is the "Babtiste" but does not look like your Banana Mango.
This next mango I am not sure if its a Haitian variety but looks similar to the M. Frances, but is larger, has less fiber and is more citrus like in flavor.
The Pascual. warning must be viewed on a 52" computer monitor.
So far this year the only mango I have eaten that I liked was the Pascual, if you crossed an Orange with a Mango it would taste a bit like that, plus very little fiber. They can get really big, but do not get those black specks, or get yellow like the Francine. they basically just get a lighter color green.