I’m going to agree with both sides here.
Our experience, here in rural NJ, reflects that of soxmom…our local public school is WHITE. The Princeton-area K-12 private school our girls went to through 8th grade was much more diverse — racially, but I think also socio-economically. It had kids of color whose parents were well off and also a good number of kids who I’m assuming were on scholarship. As a mixed race family, we felt better about sending our kids to a school with a higher percentage of minority students (in addition to all the other upsides of this private school vs. our LPS).
However, again as a minority parent, I do appreciate the efforts of my younger daughter’s school to focus on diversity. I’m surprised the school wasn’t mentioned in the NYT piece as it is in the orbit of NYC. The all-school summer reading book was “Wonder”, about a kid with a cranio-facial anomaly. I read it and really enjoyed it…it made me think about how it’s human nature to create the “other”…people who “are not like me/us”. Whether that’s due to cues of skin color or clothing or some other trait…we all do it. I don’t know if it’s a light-switch thing, where you have one meeting or speaker or even day of diversity and everything is 100% perfect, but I do appreciate the effort to at least start/continue the dialog on this front.
Note that the schools mentioned in the NYT article all (at least to me) have the air of being very progressive (Friends schools are Quaker and they are extremely progressive/liberal)…so I think this “movement” (if you can even call it that) is that widespread among private schools/BS.