It actually occurred to me that Taylor could write about losing the role and it could be this album's Better Than Revenge, but I think she's reached an age now where she can take the disappointment in a mature way; it's not like she writes a song every time she loses an award.
Also, while I do think she has the album mostly written, she'll keep writing songs for the album for as long as she possibly can; I'm pretty sure I've heard that Forever & Always and The Story of Us were both last minute songs written only a few months before album release.