One of the biggest promises of digital books is the ability to continuously update, correct and improve the text. The author catches a typo after the book is published, they can correct it without waiting for a new edition of the book to be published. A fact is discovered to be wrong (or changes after the book is published), it can be changed.
Unfortunately, the way Amazon structured it book updates means that up until now, when a book was updated the reader lost all notes and highlights from the old edition of the book. Amazon learned that they need to ask for permission to update a book because of that. So this is what the email used to look like from Amazon