Luke 21:21 proves you wrong.
(Luke 21:21) Then let them which are in Judaea flee to the mountains; and let them which are in the midst of it depart out; and let not them that are in the countries enter thereinto.
As we see above, Jesus only warns those in Judaea. He also tells them not to go to Judaea.
The discussion was in regard to what will happen after the great tribulation is over:
Here we see that signs will be seen in the sky AFTER the great tribulation is over:
"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" (Mt.24:29).
And the following passage describes men reacting to those signs in the sky and being in fear of things which will be coming on a much larger area than Israel, and which will take place after the great tribulation is over:
"And there shall be signs in the sun, and in the moon, and in the stars; and upon the earth distress of nations, with perplexity; the sea and the waves roaring; Men's hearts failing them for fear, and for looking after those things which are coming on the earth (oikoumene)" (Lk.21:25-26).
There was never a large harvest that happened on a large mass of land after Jerusalem was destroyed in 70 AD.
Well know preterist author Gary DeMar had this to say about the meaning of the Greek word
oikoumene:
"The case can be made that 'oikoumene' is used exclusively for the geographical area generally limited to the Roman empire of the first-century and the territories immediately adjacent which were known and accessible to first-century travelers. When first-century Christians read the word 'oikoumene,' they thought of what they knew of their world" [emphasis mine] (Gary DeMar, "The Gospel Preached to All the World, Part 3 of 4; The Preterist Archive).
We can also see that there will be a world wide judgment at the end of the age because He compares that with the world wide flood:
"But as the days of Noah were, so shall also the coming of the Son of man be. For as in the days that were before the flood they were eating and drinking, marrying and giving in marriage, until the day that Noe entered into the ark, And knew not until the flood came, and took them all away; so shall also the coming of the Son of man be" (Mt.24:37-39).
That judgment was not limited to just a part of the world but instead to the whole earth. And that is why the Lord Jesus compares His coming to the Noah's flood.
And that is exactly why the Lord Jesus said the following:
"And take heed to yourselves, lest at any time your hearts be overcharged with surfeiting, and drunkenness, and cares of this life, and so that day come upon you unawares. For as a snare shall it come on all them that dwell on the face of the whole earth" (Lk.21:34-35).
All the preterists do is to try to change the meaning of the Greek words
kosmos and
oikoumene to mean Israel.
The trouble with this is the fact that no Greek experts agrees with their definition (and not even their own, Gary DeMar). The other problem is the fact that both of these Greek words apply to events which will happen after the great tribulation is over. History speaks of no such events that happened after the destruction of Jerusalem in 70AD.
You answered NOTHING about this.