That is true. However, the US immigration system seems to select for the affluent, the skilled, and the already the successful. Many of them come to the country with existing contacts in positions to aid them through the process, and with specific plans. That means that many of these migrant are able to leapfrog many of most insurmountable structural barriers that black Americans face in terms of capital, debt, skills, policing, and access to an affluent social network by the simple act of being from anywhere else than America.
When they (the affluent ones to whom I'm referring) establish themselves and settle down, they're then in a position to shelter their children from many of the structural inequities faced by the black community writ large, such as access to quality schooling, housing, and living in overpoliced areas.
This does not mean that the descendants of black migrants are immune to racism in the US. Indeed, even the most affluent family can scarcely hope to protect their children from the overt, and even covert acts of conscious and unconscious racism perpetrated by both individuals and our institutions.
But affluence does open doors, and can be used as a buffer against the most systemicly insidious elements of America's segregationist past.
Is that something that Caribbean nations should address, rather than USA? Frankly I don't see how policies that don't benefit ADOS meet the ethical burden that USA universities (especially those such as Ivy League universities who historically benefited from slavery in USA) would seem to have.