From about 1992 to about 2008, I lived in Mill Park, Vic.
My neighbour in the early days, worked at what was then a Daily Juice plant in South Morang. Semi loads of oranges came down from Mildura and were turned into juice. The plant was bought by Golden Circle and continued this practice for a number of years.
Then they started importing (if I remember what the neighbour said correctly) an amount of Brazillian orange juice concentrate, that was rehydrated and mixed with a reduced amount of Australian juice, then eventually there was no Australian juice in it at all.
Unfortuantely, most Australian consumers look at "what is cheapest" not where it is made or which is the healthiest.
Hopefully recent events will jog people to change their focus, but I doubt it.