It is.
And, knowing that the new heavens and new earth is the new covenant, isn't some recent fad like Dispensationalism.
People have known what the new heavens and new earth are for over 1,500 years:
"All authorities concur in the declaration that "when all these things should have been done" "The End" should come : that "the mystery of God should be finished as he had declared to His servants the prophets" : it should be completed : time should now be no more : the End of all things (so foretold) should be at hand, and be fully brought to pass : in these days should be fulfilled all that had been spoken of Christ (and of His church) by the prophets : or, in other words, when the gospel should have been preached in all the world for a testimony to all nations, and the power of the Holy People be scattered (abroad), then should the End come, then should all these things be finished. I need now only say, all these things have been done : the old and elementary system passed away with a great noise; all these predicted empires have actually fallen, and the new kingdom, the new heaven and earth, the new Jerusalem--all of which were to descend from God, to be formed by His power, have been realised on earth" - Eusebius, Bishop of Caesarea, circa 295AD