>It seems that multiculturalism would be instructed in the discipline of Geography and not Languages.<

I'm of the opinion that certain things should be taught in all disciplines and not be considered the preserve of one discipline.
For example, when I was at school correct use of English (the school language) was an integral requirement of lessons in any subject - or at least any subject that used English. I would lose marks in a science essay if I spelled (spelt?) a word wrongly, or wrote incomplete or unclear sentences. This seems to me to make the school environment reflect the real world - where you need not only the correct information but an ability to present it credibly.
Multiculturalism is perhaps more of an ideological wish or attitude than a 'future success factor', but personally I'd like to see it in the fabric of teaching in the same way.