I think that's a hard question to answer for a variety of reasons. Possibly the biggest unknown is how tolerant the current generation of Americans really is. Baby boomers were born and raised during the height of the Civil Rights Movement which means that a lot of them might know that racism is wrong but they still "inherited" some of the prejudices of their parents. Thus, the fact that white flight has continued to be common 50 years after the fact is not all that surprising.
However, I would argue that the majority of baby boomers probably made some effort to raise their children without prejudice. Therefore Gen Xers and Millennials are probably more tolerant of living in a diverse neighborhood. These generations have also grown up in a media environment saturated by both implicit and explicit messages regarding diversity.