I agree.
Mark 9:2 And after six days Jesus taketh with Him Peter, James, and John, and leadeth them up into an high mountain apart by themselves: and He was transfigured before them.
I believe Jesus was showing Peter, James, and John how it will be at His Second Coming, at the 7th trump.
Jesus’ physical body was transformed into his spiritual body. So why would Jesus say, "after six days"? Peter gives us a clue in:
2 Peter 3:8 But, beloved, be not ignorant of this one thing, that one day is with the Lord as a thousand years, and a thousand years as one day.
The Millennium will start at the end of the sixth trump; there will be no more physical bodies after that because we will all be changed (transformed):
1 Corinthians 15:51-52 Behold, I shew you a mystery; We shall not all sleep, but we shall all be changed, in a moment, in the twinkling of an eye, at the last trump: for the trumpet shall sound, and the dead shall be raised incorruptible, and we shall be changed.