South Africa isn't coming back to NZ/AU Rugby.
It just doesn't work for them TV wise or scheduling wise.
NZ rugby union has a real timezone problem... nothing fits with them.
Australia? Sure, but few care about RU there.
Asia? Well, tough market to crack, even more so with America.
The Pacific Islands? No way there's any TV money coming from there!
No - Rugby Union's REAL big money is I Europe/South Africa and they have THE WORST timezone for NZ.
TL : DR version, all NZ RU has is basically pimping out the All Blacks to Europe/South Africa (and a little in USA/Japan) for cash.