I just want to add that the discussion of whether the specific policies were right or wrong doesn't belong here.
Australia does have a lot of Chineese people in its history, particularly with the 19th century Gold Rush in central Victoria; However one of the first things the federal government enacted upon its formation (in 1901) was the Immigration Restriction Act 1901 - a key plank in what would later become the "White Australia" policy, partially in response to racial antagonism in the goldfields. This act would not be fully repealed until 1973.
The act particularly targeted Chineese and Japaneese imigrants, discouraging them whilst encouraging immigrants from European nations.
Easing of these restrictions did occur throughout the 50's, however non europeans were not permitted to become citizens until 1957 (and at that point still had to show 15 years residency), and entry restrictions for asians relaxed in 1964. However in 1966, there were still only 746 non-european immigrants to Australia that year, the effects of the change in policy would take a fair bit of time to trickle through.
Depending on where exactly you draw the divergence line, either the full effect of the White Australia policy could be in place (a trickle of Immigrants, and citizenship not possible), the easing of its restrictions could be partially in place (a trickle of immigrants, and Citizenship possible after a long time), more or less revoked with little effect, or a result similar to today.
However, it is worth pointing out that in 2001, only 3.2% of Census respondents indentified themselves as of Chineese decent. In contrast, 4.3% identified themselves as German, and 5% as Italian. As such, I couldn't see much resistance from a Chineese commander in pushing the button.