"The issue of USA citizens attending is out there. I hope they can resolve it."
A number of years ago the Association of Black Anthropologists, a part of the American Anthropological Association (AAA), met in Cuba for their meeting. I imagine the same stipulations might be required and if needed a prospective participant could contact them about the procedure. That was before, however, before the "war powers" act invocation which ironically, disallows the US Coast Guard from the right to slow down ships in commerce or to set speed limits, particularly cited around a right whale nursery between Campobello and Grand Manan Island and migration route between Florida and the Bay of Fundy in Maine, New Brunswick and Nova Scotia. Nearby in Eastport, Maine a refinery was once proposed and fought off in the 1970s, now a liquefied gas terminal has been proposed in the area.