I think the flashback chapter to the family history sounded odd too. I'm not sure if it smells of editorial handiwork, though. Depends on the editor. Some use a light touch, others push for more. The chapter felt forced to me because it was so, so overwrought, like there needed to be a pumped wordcount (which happens in some houses; certain imprints have a strict wordcount. Novels are so many words, novellas are so many, etc.).