Is the lack of Old Testament reference in the prison epistles purposeful?

Les explains that once the prison epistles and higher or deeper church truths are in view, the demarcation between Jew and Gentile is no longer the issue, because God now deals with the whole human race on one level. Every saved person enters the Body of Christ on the same level, Jew or Gentile, and the Jew has lost his identity for the church age. Les says the purpose is God bringing Jew and Gentile together into one Body, with no difference. He notes that many Messianic Jews turn away from this Pauline teaching, trying to return to former privilege, but a Jew must be saved as a sinner, like Gentiles. In Ephesians, Philippians, and Colossians there is no dividing between Jew and Gentile and no Old Testament reference, and that is for a purpose. Les also connects this to getting out of the four Gospels and into Paul's writings, since the Gospels are still 90% Jewish and set aside, though not to be thrown away, and progressive revelation must be kept in perspective. God is no longer making reference to the Jew or the Old Testament, for His own purposes.