This also comes from the review and makes clear that an actual first century origin is the most remote possibility:

"The translator states that it could be a modern forgery (tests still have to be conducted on the manuscript); that it could actually date to the tenth or eleventh century but still be a forgery in that it was not originally composed in the time of Jesus as stated; and finally--and most remotely--that it could be a copy of something originally dating to the first century. The most remote possibility is the most intriguing and cuts two ways: It would deal a blow to both Christian believers and to the mythicists who don't believe in a historical Jesus."

The last sentence is quite provocative, even if from a purely hypothetical perspective. Assuming an actual manuscript from the first century was ever found which debunked the miracles of Jesus and his resurrection, would atheists gleefully accept it as a proof against Christianity, or would they dispute its authenticity because it attests the reality of a historical Jesus?