This is the type of title that I considered sensationalized. "Before I die" is a cliche only used to grab attention, because obviously there are no lists of books to read after one dies.
Maybe you’re reading it too literally. To me it just means “I don’t want to die without having read this books”.
I wonder how many different types of bucket lists there are. This is a "to-read" bucket list; I've definitely seen or at least heard other people opine on "to-visit" bucket lists. The more traditional "to-do" bucket list sometimes includes places to visit, but also a more wide-ranging list of activities and experiences.