Not a bad concept. Top level teams to different locations and several teams exposure to a top level opponent...
However, id be more interested in a 9s World Cup with qualifiers spread out rather than in just one place.
EG, send 3-4 teams to a location (Fiji, Bali, whatever) to play a round-robin then the winner goes on to a big final the next week. These locations get their games, but they have greater meaning than just the random exhibition.