I think she meant she'd get more honest and unbiased reviews, especially given all the backlash with The Casual Vacancy last year. Most of TCV's reviews were comparisons to Harry Potter and about Jo Rowling herself, and few just focused on the story. Since no one knew that TCC was hers, and believed it was just some random unknown author, they could review just on the book and not what the author had done in the past (and from what I can tell - I'm only early in the book now - the reviews are FAR more favourable for TCC than they were for TCV).