I don't know the load factor on this routes but Qantas was very vocal about introducing the A380 on that route. Maybe they also saw some traffic going via DXB? This might also be part of a wider plan to gain approval for more international codeshares in southern Africa. When they announced the A380 they also introduced some domestic codeshares on Airlink with the view to gain approval for a wider network across southern Africa.

https://www.qantas.com/au/en/qantas-...s/airlink.html