It's true but America is much larger than those nations, allowing them to disappear into the multiculturalism. I expect them to be relocated into areas with common cultural/social norms. Don't underestimate common food and climate.
Europe got a rush of almost entirely military aged single males. I don't think that will be the case in this situation.
I think the tribal Afghans fit in American society more than in a place like Austria, which is even less open to foreigners than Germany. It will be much easier for them to pick up English. Surprisingly Wikipedia page was rather thorough on Afghan-Americans