I read through the article but found the authors point muddled. They kept switching between the points they were arguing, which made it less persuasive.
Specifically, they make many references to the term being racist. But they mostly argue that the term is reductionist to African history, and let us conclude that is how the term is racist. But I don't know that many historians or serious scholars are using the term to describe the history of Africa. It certainly isn't a term I recall from my anthropology or history classes, though I'm now some years removed from them. Instead I remember "North Atlantic slave trade" sometimes in conjunction with the Spanish silver trade.
So I'm not sure who their audience is. Who is going around making claims about African history using a very nondescript term? Any history buff could tell you that the notion of African is just as complex as Greek given the span of culture of the old Greek kingdoms. Is it the general public? But if so, don't most people use it to denote a time period, e.g., before 1700?
So the lack of framing and structure leaves me really luke warm to the article. They don't do a good job of explaining the context of the terms use that is problematic, and they don't structure their arguments well. They use inflated language for its own sake, not for the sake of scholarly precision or clarity, and they leave too many things as unspoken assumptions.
I suppose if the main point is the term lacks precision, I agree. But so do many terms we use to describe epochs of history. China before the opium war, post-civil war America, etc. These are just proxies for time period references that would be used before detailed explanation of a before, after, and causal link to the event specified.
I feel like the author has a point here that could be made significantly better by someone else.