Simmons maintains that the old heavens and earth were "symbolic of the covenantal system embodied in fleshly Israel and the Mosaic law". I would agree with this statement however I personally do not believe the present heavens and earth passed in 70ad unlike most Preterist assume is true. I believe it is representative also of those outside of Christ, the ungodly and believe it is reserved for those who have not been born again. I believe the present heavens and earth also represent all false religion and modern Judism which continues to bind, and result in a shift away from a Christ focal point. Maintaining the passing occurred in 70ad as Simmons maintains, results in the ungodly being found worthy or righteous to dwell in the New Heavens and Earth. Simmons seems to omit this from his book Consummation of the Ages. I believe his view of passing old things and the beginning of new things in 70ad is the core issue resulting in Universalism within Preterism.
Kurt Simmons on Rev. 20:11-15
The heavens and earth stand for a system ordered and ordained of God. The old heavens and earth were symbolic of the covenantal system embodied in fleshly Israel and the Mosaic law. More than this, the old heavens and earth answered to the elements of the world from and after the fall of our first ancestor until the restitution and regeneration of all things in Christ. (Gal. 4:9; Col. 2:20; Heb 5:12; 6:1-2; Matt. 19:28; Acts 3:21) Death reigned from Adam to Moses. (Rom. 5:!4,17) The world lay under the power of sin.
However, until the great consummation at AD 70, the church was still in expectation, not possession, of its inheritance as looking for the adoption and redemption of their collective body. (Rom 8:19-23) For the church temporal, this meant redemption from sin and their manifestation as the sons of God by the casting out of National Israel; for the church ad requiem, this meant resurection unto eternal life: These would recieve at the passing of the old heavens and earth. This is the earth and heaven depicted here, fleeing from the face of the throne.
Kurt Simmons on Rev. 20:14
Death and hades were the last enemies to be destroyed. (1 Cor. 15:26) Death and hades have no part of the new creation under Christ. During the dominion of sin, man was separated from God in life, and in death was sequestered in hades. However, by his substitutionary death and atoning blood, Jesus "abolished death, and hath brought life and immortality to light through the gospel." (2 Tim 1:10) "Death is swallowed up in victory. O death, where is thy sting? O grave, where is thy victory? The sting of death is sin; and the strength of sin is the law. But thanks be to God, which giveth us the victory through our Lord Jesus Christ." (1 Cor. 15:54-57) Although death and hades are now destroyed and Christians go on to be with God in heaven after death, the specter of the second death remains for all that fail to obey the gospel of Christ.