What would have happened to Paul if Peter had not remembered the Cornelius event at the Jerusalem council?
Had Peter not remembered Cornelius, the Jerusalem council would not have permitted Paul to return to Antioch with freedom to preach his Gospel. They would have chased him and plagued him every inch of the way, resisting his ministry. Peter's recollection of God saving Gentiles without their demands defended Paul.
Les teaches that while God absolutely wanted the house of Cornelius saved, the bigger purpose was to come to Paul's defense in the Jerusalem council. If Peter had not remembered what happened at the house of Cornelius, they never would have let Paul go back to Antioch with freedom to preach his Gospel. They would have chased him, as they even did anyway, and would have plagued him every inch of the way. But they did not, because Peter realized that twelve years earlier God had shown him He could save Gentiles without going through all that they demanded. Peter rose up and reminded them of the earlier event, and this testimony protected Paul's freedom to preach his Gospel.