Revelation 14 is the gathering from heaven and earth which occurs at the 6th seal. Here we see He sends His angels.
No, that Rev. 14:14-16 harvest was of
the Son of Man alone reaping the "earth". It says nothing there in those verses about gathering the saints from the four winds of heaven yet, as it does for the later harvest which you brought up in Matt. 24:31 where the angels do the reaping.
These were two different "harvests". The first sickle harvest in Rev. 14:14-16 was the Matthew 27:52-53 resurrected saints, which the resurrected Christ Himself brought out of those broken-open graves around Jerusalem on that same day that He arose.
And that harvest of the 144,000 First-fruits Matt. 27:52-53 saints preceded the "wrath of God" harvest of Israel the "vine of the earth" (in Rev. 14:17-20) which was crushed outside the city of Jerusalem till the blood ran bridle-deep in the AD 66-70 period.
Israel is found as grapes.
Yes, Israel was quite often referred to by the "grape" comparison: "The vine of Sodom", which yielded "wild grapes". Israel was compared to a vineyard in the prophets which God had originally set up, but which did not yield the fruit He desired. This is why the Rev. 14:17-20 sickle "harvest" of the "vine of the earth" is specifically the nation of Israel being crushed in the winepress of the wrath of God. Those "days of vengeance" were dedicated to that specific nation of Israel in AD 66-70, in retribution for Jerusalem slaying the prophets and servants of God, and for betraying and murdering the Son of God. They shed the blood of saints and prophets, so in just recompense, God gave them blood to drink in those "days of vengeance".
They are not talking about Jerusalem as we can see in the previous chapter.
21 And it shall come to pass in that day, that the Lord shall punish the host of the high ones that are on high, and the kings of the earth upon the earth.
22 And they shall be gathered together, as prisoners are gathered in the pit, and shall be shut up in the prison, and after many days shall they be visited.
23 Then the moon shall be confounded, and the sun ashamed, when the Lord of hosts shall reign in mount Zion, and in Jerusalem, and before his ancients gloriously.
That
was Jerusalem being referred to where the evil angelic hosts of the high ones would be imprisoned (as in Rev. 18:2). That Old Jerusalem which became a "habitation of devils" and "a prison for every unclean spirit" would be destroyed and God would be revealed as the ruler of
the New Jerusalem reality in which we believers live today.
"Mystery Babylon", guilty of the shed blood of the saints and prophets, is called "that great city", and John wrote that "the great city" was "where our Lord was crucified". Ergo, "Mystery Babylon" in Revelation is Old Jerusalem.
You should probably read this chapter
Zech 14
16 And it shall come to pass, that every one that is left of all the nations which came against Jerusalem shall even go up from year to year to worship the King, the Lord of hosts, and to keep the feast of tabernacles.
I have. Many times. Zechariah's prophecy from chapter 12-14 is the prediction of the destruction of Old Jerusalem in the AD 66-70 period, accompanied by Christ's second coming return in AD 70. That return was followed by continued history in a "year to year" worship of Christ Jesus in the New Jerusalem reality, which we currently occupy. The "feast of tabernacles" is emphasized in these verses because that is the timing for the next, third resurrection "harvest" at the close of fallen mankind's history on this planet.
The seals are not opened. That should be apparent to anyone.
The seals were all opened long ago according to the writer John. Both the introduction and the conclusion for the book of Revelation announced that those events predicted for the future were for a time that was
"ABOUT TO BE hereafter", and that the time for their fulfillment was "
AT HAND" (Rev. 1:3 & 19, 22:10). Those phrases tells us that John's first-century readers would experience all those things playing out in their own time frame - not in our future today.
The only predictions in Revelation that would apply to our own future are found in the "sealed up" prophecies of Revelation 10:4. That's it. John didn't write them down, because those predictions did not apply to his own first-century readers, but to generations to come.