My interpretation of the article is that there are two parts.

• Those permanent residents (from select countries) who are still using their international license will be driving illegally, since the license won’t be valid anymore, and
• The people wanting to convert their international license (from select countries) into an Australian one will need to sit the Australian exams

So, those that haven’t converted their licenses will need to do so, and sit an exam to get the Aussie licence. But it sounds like the ones that have already converted the license and are driving on an Aussie license will (should?) not be affected.