New, as in He did not already decree it to happen before the foundation of the world? No. He is working out His plan in history but His actions in history flow from the divine decree. The God of the Bible doesn't make mistakes or have a plan B. He doesn't have to try to fulfil His promises while considering the supposed “libertarian free will” of his human creatures. If open theism is true? Why should I have any confidence at all that God will fulfil any of His promises to me in Christ? How can He guarantee my salvation if it's possible something He did not foresee spoils His plan?