They simply reported the health  ministers view on the matter. They are preparing for 25 percent of Australians to get it with 84 percent presenting as mild cases, which is cool if you are in that 84 percent out of the 25. The rest will be in intensive care with a fatality rate of 2 to 3 percent. That is the health ministers view of it after consultation with scientists and health professionals. As many countries including the US are now experiencing cases from unknown origin and there is an incubation period of around 2 weeks I would suggest that it is spreading rapidly by those who dont even know they have it. I reckon we will know how serious its gonna be in around 2 weeks.
The people who have died and who are dying from it are the elderly, smokers or those with reduced lung capacity and of course those with compromised immune systems. The main issue for me is that I doubt whether we have the health resources  to put an extra 2 percent of the whole population into intensive care.