No, it's blackwashing. I read that the books didn't have any of this and it was the producer of the show that decided to do it.
I admit to being a reader of the bodice ripper genre since I was a teen, as well as having a degree in Medieval European and Middle Eastern history. The book series this was based on started around 2000. It is in a subgenre of Historical Romance called Regency Romance. Ergo, it is set in a specific period of time in England. One of the first things said about the male lead in the book is" "He was a sturdy, healthy boy with glossy brown hair and clear blue eyes."
There is nothing racist about being befuddled when a period piece set in a specific time in history has things in it that are inaccurate. And yes, obviously, everything in these books are not true, though the authors usually do extensive research to try to be as accurate as possible. The issue is they are making it impossible to ever tell an accurate historical story again because you can't have all white people in anything. In current year, you can't even make something about Henry VIII without making one of his wives black. I am fascinated and have studied in depth the Norman Conquest, but I guess I will never see a true representation of it on film again in my lifetime because of politics.
There are countless rich and fascinating books, historical events and mythological tales that take place in non-white European settings. I would love to see more of those put on film. There are even historical romances set in the British Isles and Europe and the Old West where one of the characters is not Anglo-Saxon/Caucasian and they actually deal with the discrimination that the individuals faced in that time period. Those are interesting. Randomly casting a non-white actor for a character that actually wasn't for no other reason than diversity points is just boring. Especially when nothing else about the character actually changes. And, especially when it is always white characters (and usually redheads - stop the ginger discrimination!) that are replaced in their own stories.
The Bridgerton books are one of the highest selling and most popular Romance series in this century. Instead of creating something new or using one of the other books/series I talked about, the showrunners/producers/directors, whatever are using an established, popular IP for their own agenda with no thought, care or even respect to the original material. Something we have seen over and over again in the last 10 years. Though, in this case, the author has come out with glowing praise for the changes. Whether she is obliged because of contract reasons or is on that side of the cultural spectrum, I have no idea.
My family are Irish/Scandinavian and Native American - my mom's grandparents were born and raised on a rez. I would be equally aggravated if it was either of them being replaced in a story.
And I know that was more than anyone in this thread cared about, but I thought I would bring the perspective of someone who has read the books.