I never saw the Soaps and Serials books, but I can comment on Saga of Seaview Circle. The author took liberties when filling in certain blanks about characters' pasts, especially characters that were not that prominent. I don't think she was trying to revise history; the details she included only helped the writing sound like a genuine biography (as the book was written as if these were real people). I believe she only did this when the show provided absolutely no clues in dialogue, or producers had not provided any such information in character bios, such as colleges characters attended or the names of their parents. The book was written in the period leading up to the seventh season cliffhanger, so all the life stories end at that point. Paige had just shown up on their doorstep to announce she was Mack's daughter, but had not used her mother's name. Since Mack had never mentioned his affair with Anne (and knew nothing about Paige), the author of the book had to make up some of the story. She even named Paige's mother "Pamela Matheson" rather than "Anne", which tells me the producers of the show had not ironed out all her details yet when the book went to press.