Did the coming of the Messiah cancel the Old Testament?
No. The coming of the Messiah did not cancel the Old Testament; it fulfilled it. The Abrahamic covenant brought Israel to the place of Messiah's coming, and progressive revelation builds on what came before rather than abolishing it. When Israel rejected the Messiah, God sent Paul to the Gentiles.
Les teaches that Scripture is progressive revelation. Just as Paul received new revelations, that did not cancel everything that had gone before; it built on it. The Abrahamic covenant brought Israel to the place where the Messiah came. When the question is asked whether that cancels the Old Testament, the answer is no—it was all fulfilled. Then, when Israel according to prophecy rejected the Messiah, God saved Paul and sent him far hence to the Gentiles. Jesus did not teach the twelve to go to the Gentiles with the gospel based on His death, burial, and resurrection, because it had not yet happened. So the Messiah's coming fulfilled the Old Testament rather than canceling it.