The big difference between black slavery in America and the practices against Jews and Japanese during WW2 and the Native Americans is most of the practices during slavery were legal at the time.

Just like you can't sue the airlines for making you breath second hand smoke on flights back in the 80's,I don't think you can sue the insurance companies for profiting from a legal institution. Maybe a constitutional argument could be made, saying that the practice was actually unconstitutinoal, but it seems so obvious a argument to me that I've gotta think it's been considered and rejected by legal experts.

Reparations seems mostly a moral issue to me anyway. I dunno if the govt can be forced to do it, I doubt they'd voluntarily do it, but the govt has never formally given black people in America any closure.