*sigh* This sort of thing used to baffle me, until I realized just how woefully subliterate (in general and especially historically) more and more people are nowadays. From a book blurb (for a book probably best avoided):
“. . . a cop finds a trove of ancient documents that may — or may not — be an undiscovered Shakespeare play. . .”
“Ancient,” used in reference to historical documents, almost always refers to Classical Antiquity — ancient Greece, Rome or the Middle East, etc. Sometimes it is loosely used in reference to medieval and earlier times, mostly by folks who are only moderately aware historically.
Shakespearean manuscripts could not be considered “ancient” by even the loosest, least meaningful sense of the term, since Shakespeare died just under 500 years ago, smack in the middle of the Renaissance.
Since these book blurbs for self-pub books are most often written by the “authors,” I’d say giving this book a pass might just be a sensible time saver.