Yichusdik:
Sorry for not answering you sooner.
Let me try again. From what I perceive, there were two types of Gedolim throughout the era right before churban Europe.
One who HaShem in His infinite wisdom granted crystal clear foresight into events about to unfold. It’s not a secret. Anyone know of R. Elchonon’s droshos (I think the Chafetz Chaim too). The Meshech Chachma. Others too. I know of a Chassidic Rebbe who spoke openly of events about to unfold..
Then there were others (I think a lot more) who HaShem in His good judgment decided to cloud their spiritual venues of knowledge (one reason as I mentioned before). So as great as they were, as powerful as they were before, they were totally at a loss during that time. As I wrote a direct intervention from HaShem ????? ???? ?????.
Now it’s regarding the first type, who you’re referring to, you’re asking why they didn’t tell them to leave. Good question. I don’t know. Maybe you answer.
I tried one. Let me back it up. It’s no secret of the total assimilation prevalent in those time. It’s not as you wrote “possibility” or “spiritually being weakened”. We’re talking about a definite TOTAL ASSIMILATION. Do you’re math. How many immigrants were Jewish, how many can you find of them today? I don’t have any numbers or statistics, but I’m told it was a COMPLETE assimilation. It’s no secret how all Gedolim of the past viewed America then, it was considered to be a spiritual wasteland, and they sought to prevent anyone from immigrating. So I can understand why one Gadol not outright insist on others to leave to Americe en masse, (some privately were actually advised to do so, the Gedolm knew their strengths). But as a rule I could well understand, the chance of a COMPLETE spiritual demise was DEFINITE, they chose to do what they did in all previous generations. Kidush HaShem.
Remember the words we uttered not to long ago: ?? ????? ?????? ????? ??????? ????? ?????? ????? ???? ?????.
<Theory One>
Let’s try another one. Yidden did hear now and then, from Gedolim, from the existing media a bit too. Why didn’t they escape. I wasn’t so simple. Can’t just get up and cross the ocean. A lot of people became entrapped because of their belongings, families etc.
<Theory Two>
Another one. There is no Nevuah today. There is Ruach HaKodesh, but not a pristine Nevuah. Perhaps even those in the know maybe thought there would be chance to escape. Or maybe those hearing the about the impending doom thought so.
<Theory Three>
To sum it up, I don’t know. What I do know is that a good amount of Gedolim foretold the impending catastrophe about to unfold. And also that not so many people made it here to these shores.