I haven't read Tomb of Annihilation, and I have no plans to buy it, so I don't know how well the article's criticisms apply in context; but assuming that it presents the material fairly, its conclusions are reasonable. I looked up Graeme Barber's review at https://pocgamer.com/2017/10/13/tomb-of-annihilation-review-part-1-chult-in-5e, which is sharply critical of the way the setting was executed.
The sum of the criticisms in both articles, as I read it, is that Chult remains a mash-up of African stereotypes. 5E avoided being blatantly offensive (apparently the 4E book actually described the Chulteans as a mix of "noble savages" and "depraved cannibals," which... I have no words), so that's progress, sorta. But it's still a stew of tired pan-African tropes.
One point that Barber makes is that ToA kept the setting material to a minimum, and that this has a very different impact on a setting like Chult which has been handled sketchily (in both senses of the word) in the past, compared to the Sword Coast which has been exhaustively detailed across the editions. I can understand WotC's reasoning here: They said they thought players and DMs would be bored by a big focus on the setting, and I think they're right. But that doesn't excuse being careless with the setting material they do include; quite the contrary.
(Again, this is assuming both reviewers are fairly presenting the content of the book, which I haven't and probably won't read.)
I like Barber's arguement, but honestly most of the settimg has been letting go to waste, so why be surprised that so is Chult.
So much opportunities gone to Waste.