From Tablet ignites debate on messiah and resurrection:

"His mission is that he has to be put to death by the Romans to suffer so his blood will be the sign for redemption to come," Knohl said. "This is the sign of the son of Joseph. This is the conscious view of Jesus himself. This gives the Last Supper an absolutely different meaning. To shed blood is not for the sins of people but to bring redemption to Israel."

Very interesting article. The true Gospel is that Jesus's death accomplished both atonement for the sins of the people and by that, redemption for Israel. (i.e., those who are, like Isaac, children of the promise, and from every race, nation, tribe, and tongue.)

In short, the "new" discovery just confirms what we've known all along: "that Christ died for our sins according to the Scriptures" (1 Corinthians 15:3).