TotallyEffed said: "Is this AI?"
As people in the replies have said, what probably happened was that a ghostwriter was hired to write the book, and the ghostwriter asked a chatbot for things Erivo said about body image in interviews, and it grabbed something by Grande by mistake.
The fact that something this lazy, cynical, and obvious went through multiple levels of copy-editing and fact-checking, and ended up printed on the page is deeply hilarious.