Hello Dave. This was the interpretation I also got as I read through the Bible. I'm not saying its not a viable interpretation, but did you consider that when Paul wrote about the last trumpet to the Corinthians, that the book of Revelation had not been written yet? The corinthians would have never connected it to that trumpet, since it wasnt known about yet at that time.
1COR.15 [50] Now this I say, brethren, that flesh and blood cannot inherit the kingdom of God; neither doth corruption inherit incorruption.[51] BEHOLD, I SHEW YOU A MYSTERY; We shall not all sleep, but we shall all be changed,[52] 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.[53] For this corruptible must put on incorruption, and this mortal must put on immortality.[54] So when this corruptible shall have put on incorruption, and this mortal shall have put on immortality, then shall be brought to pass the saying that is written, Death is swallowed up in victory.
The above scripture points out that “we shall all be changed” as the LAST TRUMPET is blown.
MATTHEW 24 [29]IMMEDIATELY AFTER THE TRIBULATION of those days shall the sun be darkened, and the moon shall not give her light, and the stars shall fall from heaven, and the powers of the heavens shall be shaken: [30] And then shall appear the sign of the Son of man in heaven: and then shall all the tribes of the earth mourn, and they shall see the Son of man coming in the clouds of heaven with power and great glory. [31] And he shall send his angels with A GREAT SOUND OF A TRUMPET, and THEY SHALL GATHER TOGETHER HIS ELECT from the four winds, from one end of heaven to the other.
Here in Matt. 24 we find a trumpet being blown after the tribulation period. It is the "last trumpet" to be blown. His people gathered {in the twinkling of an eye}. When does this take place? Sun darkened! Moon no light!
JOEL 2 [31] The SUN shall be turned into darkness, and the MOON into blood, BEFORE the great and the terrible day of the Lord come.
REVELATION 6 [12] And I beheld when he had opened the SIXTH SEAL, and, lo, there was a great earthquake; and the SUN BECAME BLACK as sackcloth of hair, and the MOON BECAME AS BLOOD;
Pretty simple