I would have thought most of those seats would've been reserved for a tour deal.
Yeah, could be jumping the gun a bit. The $476 deal for the new route is advertised on Fiji Airways homepage and going to book now and searching the dates it says there are 2 seats left on 25th June for that deal (there are more expensive options too). Perhaps there are seats reserved for a tour and booking details haven't come out yet and there have just been a few for general sale.
Edit: And I see Fiji Airways have said on twitter more details on the tour will be announced today so I'm probably just looking into it a bit too quick.