Some of the changes are more cosmetic. Two important male characters, world challenger Helmholtz Watson (Hannah John-Kamen) and world controller Mustafa Mond (Nina Sosanya), are played by minority female actresses. Others changes in the story remove what would be considered now to be insensitive (in the book, the character of Lenina Crowne describes things as "being queer"). This is most apparent in how the series depicts the Savage Lands, turning it from an Indian reservation (full of Native American stereotypes) into a theme park.
https://www.msn.com/en-us/tv/news/brave-new-world-how-peacock-brings-aldous-huxley-s-88-year-old-sci-fi-classic-into-the-present/ar-BB16K2sG?ocid=msedgdhp