Yeah, I have no desire to debate this or to look up articles and point out where definitions are wrong, or different, or what have you.
If they're teaching this, it wasn't what I was taught over not only the course of my life, but in Con Law in law school also. Nobody reputable will tell you that "segregated high schools" ended in 2016. The communities may have drawn district lines that ensured that mostly white populations would go to school with white populations, but there is no way that blacks weren't allowed to go to school in the communities they lived in. That would be the grossest violation of federal law I can think of, and that's the formerly accepted definition of a "segregated" public school.
That we've moved into "de facto" segregation, or any other usage of the word "segregation" is a change in the formerly used definition. Is that more or less accurate? I don't think it is, but everybody's mileage may vary. But it certainly blurs the lines of what we mean when we speak of "segregation" in the meaningful sense.
In a way, our whole conversation (brief though it may be) is what the activists want. They seek to change the definition of a formerly settled concept. They seek to change the definition of a word (or say, an entire concept like "sex") an then they want you to go through the rigamarole of debating why the former concept was correct and what it means, and does it really apply in all cases, etc.
I have neither the time nor inclination to debate it any longer. But just so you know, if you're ever taking a test, "segregation," not de facto segregation, ended in 1954 with Brown.