When Australia has several cultures represented by political parties competing to preserve their culture, and the ABC has a weather girl in a hijab, then we might be approaching multiculturalism.
One of the strenths of our immigration program is its diversity; Australia has taken a little bit from each continent rather than a very high proportion from one or two countries, language or religious groups (not like some European countries which took in large numbers of 'guest workers' from former colonies or the US a century before).
While nearly half of our population are either migrants or first generation, an ethnically-based political party won't work at the state and federal level as different groups don't necessarily all get along. And what language would they need to use to communicate with other ethnic groups? English!
So ethnic politics is largely done within branches of the mainstream parties rather than seperately. And our voting system with single member electorates and two strong parties encourages this.
It's not like Canada where there are large geographic concentrations of a group (French) that are linguistically different from the rest of the country, or large American cities with Black or Hispanic majorities (though note that these can also be diverse). Ditto for Malaysia or Fiji where there are 2 or 3 big groups that by themselves are numerically big enough to divide a country. It is this factor that gives rise to division more than the proportion of people born outside the country.
Whether through design or accident, diversity is something Australia has done well in that no one ethnic group is big enough to divide a country (especially with single member electorates where the major parties have to 'catch all' to win votes).
The multicultural intellectual Left (as opposed to the anti-immigration greenie Left, who vote Green or Kelvin Thompson) sometimes criticise Liberal governments (eg the previous PM) on immigration. Liberal politicians when in opposition have sometimes warned about immigration (eg Howard in 1988) so they get the 'racist' tag.
However history has proved that when in office Liberal governments are usually high immigration governments (eg Menzies, Gorton & Howard with Fraser the main exception). Certainly business groups have nothing to lose from higher immigration/household formation; the first homebuyer might beg to differ.
Whereas those governments whose ministers or prime ministers have championed multiculturalism the most, eg Whitlam/Grasby (but more Al as Gough didn't particularly like South Vietnamese), Fraser and Keating have all been low immigration governments. The economy could also be blamed - 1975, 1982 and the early 1990s were recession years when those PMs were in office and immigration tends to drop or be cut then.
Hence the relationship between immigration and multiculturalism is not as straightforward as made out to be, even though it's linked in the public debate.
As for the ABC, is that relevant?
A better measure of diversity is not who presents the weather on the ABC (do many non-UK migrants watch it?) but the number of satellite dishes.
For this allows reception of overseas TV. It's not like in the old days when you just had the choice of 3 or 4 local TV stations - all in English. With satellite people can maintain their language and culture, and if that's all they do (like the unemployed underclasses in outer Paris) then they can live their whole life without learning much French or engaging in mainstream society.
A lot of commercial programming is driven by ratings and advertising. The ethnic media is widely read but is often 'under the radar' as far as advertising goes. And, due to Australia's framentation of language groups individually it is small but collectivity it's reasonably substantial.
Something might rate the most popular but in a diverse pluralistic society it might not rate a majority. Much like the penetration of the major newpapers and TV networks (especially in the USA where cable is big) people still watch/read but they don't command the majorities like they did 30-40 years ago.