Anecdotally, I can say living near Boston I've heard plenty of families justify their choices to move to certain suburbs or neighborhoods on the basis that they prefer the diversity over a more homogenous subdivision. Of course, equally I've met people who live in a whitebread suburb and praise its diversity because of the number of Asian doctors' kids in the schoolsystem.

I think that suggests the flaw in this simulation - sure, segregation decreases overall if -everybody- is a little more tolerant of diversity. But how does it work out if some people prefer a diverse neighborhood, and some people don't? My guess: you get a new kind of segregation between homogenous neighborhoods, and diverse ones. Kinda like you do round Boston...