Just a few thoughts. If we take that literally the term Seal of the Prophets means no more Prophets then Jesus well before Muhammad had already called Himself the ‘first and last’ ‘ the beginning and the end’ But He obviously was not meaning it literally as He spoke of His return and the Comforter and the Spirit Of Truth to come after Him.
In the Quran there are many passages below that indicate to me that Muhammad is not the last Prophet nor the Quran the final Revelation from God, and that God’s Words will never be exhausted.
But this is only my humble opinion.
Sura 31:27
And were every tree that is in the earth (made into) pens and the sea (to supply it with ink), with seven more seas to increase it, the words of Allah would not come to an end; surely Allah is Mighty, Wise.
The Words of God or Allah I believe here refers to His Revelations. My understanding of this verse in the Quran is that the Revelations from God (His Words) shall never come to an end, that is, Prophets and Revelations shall continue to appear to humanity from God after Muhammad.
In the Quran it speaks of the ‘Day of Resurrection’ and describes two significant events that will occur and makes mention of the appearance of the ‘Lord’ during the second event.
Sura 39: 66-69
But they have not deemed of God as is His due;
for on the resurrection day the whole Earth shall be but his handful, and in his right hand shall the Heavens be folded together. Praise be to Him! and high be He uplifted above the partners they join with Him!
And there shall be a blast on the trumpet, and all who are in the Heavens and all who are in the Earth shall expire, save those whom God shall vouchsafe to live.
Then shall there be another blast on it, and lo! arising they shall gaze around them:
And the earth shall shine with the light of her Lord, and the Book shall be set, and the prophets shall be brought up, and the witnesses; and judgment shall be given between them with equity; and none shall be wronged:And every soul shall receive as it shall have wrought, for well knoweth He men’s actions.
Sura 50:41
And listen attentively on the day when an announcer will proclaim from a place nearby.
Fanfare - Wikipedia
It is often played to announce the arrival of an important person, such as a king, queen or presidential leader. Fanfares are usually played by trumpets or French horns and other brass instruments, often with drums.
In the Quran the trumpet is used I believe, to announce the arrival of two Kings but Spiritual Kings or Manifestations of God.