The segregation in Sweden is real and extreme like you mention.

Back in 2005 I moved to Sweden from Germany because my wife back then was Swedish. We had to move to one of those places where there were mostly immigrants, especially when it came to the children. Our doughter always spoke Swedish but sometimes she would come home from the playground and ask us why she doesn’t speak Albanian, all the other children speak Albanian.

Anyway, the school she was supposed to go to was more than 50℅ migrants. This was when even I as a migrant said we need to move her to the neighboring school, even if it 10 more minutes to walk every time, because there are much less migrants there. So yeah even I added to the problem of segregation. It’s tough to follow your good intentioned principals when it affects your own child in a bad way.