Firstly, Ezekiel is the only prophet recorded in the Holy Bible to which God directly revealed the details about "Gog, of the land of Magog, prince of Rosh, Meshech, and Tubal, and prophesy concerning him."
None of the other prophets - Isaiah, Jeremiah, Daniel or Hosea, Joel, Amos, Obadiah, Jonah, Micah, Nahum, Habakkuk, Zephaniah, Haggai, Zechariah, and Malachi wrote so much as a single prophetic word about Gog of Magog. Zippo, Nada, None. The fact that the angel Gabriel said nothing to Daniel about Gog of Magog speaks volumes in my opinion. I would say the purpose of God the Father is inherent in this blatant omission. More on that in just a moment.
Secondly, when the angel Gabriel told Daniel (Ch. 11) about the kings of the south and north, that particular prophecy was fulfilled in the several wars between the Hellenic empires of Ptolemaic Egypt (south of Israel) and the Seleucid Empire of southwest Asia (north of Israel). These wars were fought over a period of 106 years (274-167 BC) and which culminated in the fulfilled prophecies about the precursor antichrist Antiochus IV Epiphanes.
There is no mention of the Antichrist or of Jerusalem or any existing Temple in Ezekiel 38/39. I believe these are indicators that the attempted invasion by Gog's confederation occurs during a period of time when Israel is dwelling securely (after Psalm 83, Isaiah 17 for example) but has not yet rebuilt the Temple. Like a time between right now and the start of Daniel's 70th Week and the revealing of the Antichrist with his 7-year "covenant among many."
Finally, getting back to the Lord's purpose in His prophetic word to Ezekiel. This is a really crucial point for us to consider. This coming great slaughter upon the mountains of Israel in Ezekiel 38/39 is not just to bring Israel back into faithfulness to God, but also, as the Lord declares in verse 16: (NKJV - emphasis added) "And thou hast come up against My people Israel, As a cloud to cover the land, In the latter end of the days it is, And I have brought thee in against My land, IN ORDER THAT THE NATIONS MAY KNOW ME, IN MY BEING SANCTIFIED IN THEE BEFORE THEIR EYES, O Gog."
Do you see that? God declares to Ezekiel - and to all of us living right now - that He will supernaturally reveal Himself to the gentile nations of the world through the overwhelming slaughter of Gog's entire confederated military forces and the fire He sends on the land of Magog.
First question: What purpose would there be to this for all of the gentile nations if it were not prior to the Harpazo?
And what does Ezekiel say occurs after the burial of Gog's confederate armies?
Israel builds the Temple.