Not gonna lie to you, I'm as oldschool a D&D fan as you can ever be, and I don't mind updating the older settings according to more modern standards. (Still waiting for a version of "Dragonlance" in which women aren't generally presented as idiots, for example.)
That said, this new take on Ravenloft is on the weaker side. My friendly guess is, the writers didn't really know the setting, and pretty blatant tokenism more often than not replaces more creative approaches to the genre, and to the specific scenarios. I say that in the context of this book adapting "Ravenloft", not in the context of "D&D trying to do horror": The game-related content and the trademark 5e design structure don't disappoint. It's the need to connect to the older material that weakens the book: Rather than straight out butchering classic Ravenloft - because, make no mistake, this is what's done here - it would have been nice to see the same authors try something completely new and original.
From a genre/horror point of view, I find the book rather replaceable. Other RPGs have done that better, with WotC's "Curse of Strahd" or several Pathfinder modules essentially showing how it's done. If I was looking for a new setting, these days, I would probably consider something like Troll Lord Games' "Haunted Highlands". That one is already a few years old, already, but considerably less convoluted than this new take on Ravenloft.
From a Ravenloft point of view, I feel really old. The tokenism doesn't faze me - this is a book for younger folks, and hitting them over the head with some stuff is not necessarily a mistake. That said, again, a display of love for the source material, rather than an attempt to "improve on it", would have been what I would have liked to see. I was aware that I was not going to see the White Wolf gazetteers continued - but I would have hoped that, after the very literary take on the setting we saw from the Kargatane, we would now get a condensed, play-focused version of established concepts, not just a new version that is more "inspired by" than "based on".
From an applicability point of view, I doubt that I will ever use this book as the base for one of my games. Which brings me to the book's core weakness: The writers don't seem to understand their source material.
Harkon Lukas being presented as black isn't a problem because of his race, but because it shifts the reference point. Kartakass isn't supposed to be, whatever, the Mardi Gras, it's supposed to be a pretty specific fantasy version of medieval Germany, with Wagnerian connotations, and all. That's a lot of free background to toy with as a more sophisticated DM. Taking it away cheapens the value of the content. The same for - and this seems to have been a real knee-jerker for some of the many internet commenters - the presentation of Mordent: Not a problem to make the Weathermay twins black, per se. But a problem as soon as it distracts from the intention of the original scenario. - Which is, at least to me, that Mordent is essentially the standard Bronte, "Rebecca", "Woman in Black"-kind of Gothic horror backdrop, and the players have a clear idea from the get-go what they are in on. Like the story where you are aware that your mission is essentially to slay the evil vampire in his castle

, it's a narrative all participants can place and toy with because it's heavily reliant on narrative tropes. It allows for a different kind of roleplaying than "generic" horror outside of that narrative frame, the same way players of CoC or WoD usually have a clear idea about the game they're going to play.
...And that's something 5e Ravenloft seems to struggle with, throughout all the reimagining and namedropping: It
reads as if it's a way less efficient take on "classic horror" than its predecessors used to be. Unless the writers soon supply us with a proper practical take on the new Ravenloft, in form of a proper campaign or adventure module that gives the many new changes a proper meaning
within the game, 5e Ravenloft will continue to lack "character", compared to older versions of the setting, or to other takes on the "fantasy horror" genre.
As it is, 5e RL is playable and easy to read - but it's plainly not a good adaption of the older stuff, and it's long-time value as a horror backdrop for D&D is not yet defined. As it is, it's neither a proper hommage, nor fresh enough to create a following of the kind classic Ravenloft did; on the long term, this book might very well age just like a slightly more setting-driven 5e version of 3e's "Heroes of Horror".
