The mekubal Rabbi Avraham Azulai, writes in his work Chesed L'avraham, Mayan 3 Nahar 22: "You must know that we have a tradition that on the day when moshiach will arrive in Eretz Yisroel with the ingathered Jews, he will find there seven thousand Jews." He goes on to say that after the coming of moshiach, those seven thousand Jews will reach a higher spiritual level than everyone else. When the ingathered Jews complain about this, moshiach will reply, "Hashem rewards people measure for measure. They risked their lives and subjected themselves to deprivation to come here and lead spiritual lives; therefore Hashem rewards them with a high spiritual level. You put your body and your possessions first and stayed in Chutz Laaretz; therefore your reward will be material wealth."
On many occasions the Satmar Rebbe would show this Chesed L'avraham to people and say, "I tremble when I read this. From all the millions of Jews who are there now, only seven thousand will be left!" (Yishai Buchinger, Zichronos Fun Heiligen Satmarer Rebben, pp. 46-47)
Now, it does not seem like the Chesed L'avraham is saying that there will be some massive expulsion that will leave only seven thousand Jews in Eretz Yisroel. If that would be the case, why would the Jews of Chutz Laaretz be to blame for not living in Eretz Yisroel? They tried to live there and were expelled! Furthermore, the Chesed L'avraham sounds like he is encouraging people to live in Eretz Yisroel, saying that those who live there during exile will get a special reward. Why then would he write that Hashem will bring a disaster, chas veshalom, upon the vast majority of the Jews living there?
The answer is that he does not necessarily mean there will be an expulsion or a disaster. Rather, he means that the Jews who will be rewarded for shunning materialism and living in Eretz Yisroel are only those few who want to live there no matter who is in power. But the vast majority of the millions living there today are only willing to live there because of the existence of the State of Israel and the supposed protection and opportunities it affords. When it reverts back to being a gentile country as it was in past centuries, these people, in the best case scenario, will leave of their own accord. Then, when moshiach comes he will find only seven thousand Jews in Eretz Yisroel, and he will tell the rest: By opting not to live a deprived but spiritual life in Eretz Yisroel under the gentiles, you placed your bodies and wealth higher than your souls.