There seem to be a few stories about where that name comes from, but that's par for the course when dealing with unusual place names.
Assuming for a moment that those bones are indeed from the bodies of people associated with goings on at Oak Island, why ship them a hundred and some odd miles all the way around the southern tip of Nova Scotia to Yarmouth? Why not ship them 20 or 30 miles to the southeast and pitch them over the side there? It seems like that would be less work to me. (Of course, there wouldn't be any bones on Murder Island either and that's no fun at all.)