There is a lot of misinformation in here, and several terms for which there is no evidence of racist origin or history. It's important to examine claims like these to make sure that they were thoroughly researched and not based on speculation. Adding racist origins to terms does not help combat racism. If anything, the seriousness of racism should make us even more careful to be historically accurate.
There was so much unexamined speculation behind some of these that I even felt inclined to go back and check the ones I know legitimately have racial origins, like "cakewalk." But even the description of that tradition is wrong. Cakewalks started within the culture of enslaved people as a way to blow off steam and poke a little fun at the plantation owners. They were usually held in slave quarters with just the enslaved peoples, though once in a while the plantation owners and guests would come to watch. It was also a clever way for enslaved people to "get their own back" by subtly mimicking the airs that the slaveowners put on. Cakewalks were so popular that African-Americans continued to have them for 50 years after slavery ended and there were even regional championships.
This article made it sound like cakewalks were an ordeal invented by slaveowners to put the enslaved people through, while wearing chains and even at slave auctions! This is not the case. It was a party, one of the few ways enslaved people could have any enjoyment in life. Given the staggering amount of well-documented horrors within the slave trade we don't need to twist the facts to make cakewalks seem something they were not.
I am a historical linguist and I consider the origins of language and expressions important and worth getting right. I am going to write an answer to this article point by point when I get time.