There are a lot of reasons, that basically boil down to two major policies: “notability” (ie, “should we have an article about this”) and “npov” (“neutral point of view”). The short version is “we don’t let someone with a financial stake write about a book that isn’t published yet.”

So it’s a 100% hard no on any publisher being able to do this before the book is printed. It’s still a pretty hard no after - but it’s a 100% no for “in time to print the book”.