To my knowledge there is no need to overfly the pole of the Antarctic continent proper - and it's all due to geography. Take a look at a map of the southern hemisphere - all continents are a long way north (except patagonia from which transcontinental flights do not originate anyway).
Sydney is only 33S and JNB 26S.
Between east coast Australia (there's only 1 million on the west, and they won't be leaving in a hurry for South America!) and the southern most international airport in Chile I can find (SCTE or El Tepual at 41S) the great circle route still dows not curve far enough south over its 6000nm leg to reach the ice.
The Johannesburg (South Africa) to Sydney (Aus) track takes you down as far as Heard Island before curving back up again.
Put in
the great circle mapper the following route JNB-SYD-SCTE and all should be clear.
CS
Edit: Try (Perth) PER-SCCI (at 51S near the tip of Patagonia) - that goes over the Antarctic continent, but is not a well travelled route!!!!! The map generated for that flight on the great cirlce mapper will help to answer your question too.