Just wondering why not? I had rumours it had to do with the HPOL and VPOL issue on D1 so that Australians could potentially pick up the Freeview signal since it's not encrypted and Prime has re-broadcast rights for some shows (Rugby League?) that it has no rights to broadcast to Australia? If that is the case, it seems like an easy solution would be to black out those broadcasts on Freeview when they are on. When I lived in the US that was common practice - black out games which featured the local football team in the local area while making the transmission available in the rest of the country, unless the game was sold out.
Is there another technical reason or is it just commercial?
Larry