I think that DnD is about having fun and relaxing. It is NOT about politics and being PC.
I wish we lived in a world where wanting a region full of various cultures and rich mythology to have some of that variety and mythology represented in a fantasy game that makes a habit of tapping various cultures and mythologies for ideas wouldn't
have to be a political or PC topic, but here we are.
If the author doe not like the content being created then the author should get off their butt and create some content.
Put your money where your mouth is and write a sourcebook based off just as one example the Empire of Mali that existed from the 12 to 16th century and possessed more wealth than all of Europe during that time.
First off, that's ridiculous logic. "If you've never had published work in the TTRPG field, you have no room to ever say anything about what the most popular TTRPG in the world does," is not a viable defense from criticism. Also, We don't know what the writer homebrews in their own D&D games. Even if they had come up with a bunch of awesome material, with the way the TTRP market works it's unlikely they could ever get published or see much circulation- mostly by dint of not being D&D.
Create a source book for the Numidians, the great horsemen allies of the Carthage of the ancient world. Oh wait the Numdians were Berbers, so they are probably not stereotypical enough for the writer.
Oh and by the way Mulhorand and its neighboring kingdoms are based on Egypt. Not that it matters. I am sure the author did not mean Africa, he meant sub-Sahara Africa, he meant Black.
Yes they mean sub-Saharan Africa. That's because Forgotten Realms hasn't really "dropped the ball" in depicting Mulhurond, Unther, Thay, Anuroch, and their surrounding North African/Near Eastern analogues as varied and unique nations, while singular Chult is supposed to represent all of sub-Saharan Africa. Forgotten Realms analogues for Numidians and Egyptians get plenty of coverage in Forgotten Realms and don't have to worry about all being lumped together into a singular ethnic group with a singular history, singular language, living in a singular environment that plays up how scary and foreign it all is.
Also, the idea that North Africa =/= Africa wasn't invented by the writer. It's part of a long running practice of trying to dissociate the civilizations north of the Sahara from those further south, where all the darker skinned people lived. Consequently, it leads to the idea that anything interesting of note that happened in Africa happened north of the Sahara and that anything that happened south was either not very interesting, or the work of outsiders.
Ever notice how the various civilizations analogous to north African ones in Forgotten Realms are on the far northern and eastern edges of the map while the part of the world analogous to central/east/west/south African ones are in one country on the far south west? The thinking mentioned above is so taken for granted that most people don't think of Egypt or other places in North Africa as even being on the same continent as the rest of Africa.
But it does not matter, this is an article with an agenda and reality does not belong in such articles.
The agenda here is to call attention to how sub-Subsaharan, aka "black" Africa gets portrayed in D&D. It seems pretty open about that.