As far as the thought of another holocaust, Chas V’Shalom:
During the leadup to the first Gulf War, when Saddam Hussein Yemach Shemo was threatening terrible things etc., there were those who said it would be terrible for the Yidden, like another holocaust, Rachamono Litzlan and Chas V’Shalom. The Rebbe said, in very strong words, that it would not be so; it would be only good and revealed good! See Derher Adar 1 5774 bottom of page 15 https://derher.org/wp-content/uploads/16-adar-1-5774-04.pdf which quotes among other things a Mugadike Sicha from Vaeira 5751 (completely bolded paragraph at end of Se’if 12, in Yiddish here: https://drive.google.com/file/d/1z_2SisVHMMGUhsx8vzsle_DoKMwTByAh/view and in Lashon HaKodesh here: https://drive.google.com/file/d/1Va-AtRsAiDdWw3rDQCPzRqdv8F1Wr11g/view )

Especially now, in which the year is Pey Alef, P’laos Arenu, which the Rebbe strongly hinted is like the year 5751 (the year the first Gulf War occured) and will have revealed wonders (Vayigash 5751, Sefer Hasichos 5751 chelek 1 page 214 footnote 94), it will surely be revealed good for all the Yidden, Be’ezras Hashem!

I do think it is necessary to work to combat anitsemitism in Derech Hateva (it has hit “home” for me: I currently live in Pittsburgh, where there was Rachamono Litzlan a massacre of 11 Yidden who were murdered Al Kiddush Hashem just because they are Yidden; the 2nd Yahrtzeit is coming up in less than 2 weeks). On the other hand, we must not worry and be scared about what negative things would Chas V’shalom be in the future; we must do (and be ready to do) whatever we can and must do using natural means, to combat antisemitism and do what we can to protect Yidden. And simultaneously, we must daven (pray), and keeps our hopes up, and trust in Hashem that everything will be revealed good from here on in!

Nowhere in Swados’ account of the yechidus did I see reference to the Holocaust happening in America. In fact, from the Rebbe’s explanation it seems that such atrocities are unique to the German society of that time (or any society with similar characteristics).

Here it is:

“…Was it his opinion, then, that the tragedy was not a unique visitation upon the Jewish people, and that it could happen again?

“Morgen in der fruh,” he replied unhesitatingly. “Tomorrow morning.”

Why was he so certain? The Rebbe launched into an analysis of the German atrocities in a rhetoric that shifted eloquently and unhesitatingly, often in the same sentence, from English (for my benefit) to Yiddish (for nuance and precision). He did not speak mystically, nor did he harp on the German national character and its supposed affinity for Jew-hatred. Rather, he insisted upon the Germans’ obedience to authority and their unquestioning carrying out of orders — even the most bestial — as a cultural-historical phenomenon that was the product of many generations of deliberate inculcation.”

In my opinion, the American nation can in no way be compared to the Germans of the time based on the Rebbe’s holy words, and they should therefore not be portrayed in such a context. (Especially since the Rebbe said – in many famous sichos and in yechidusen to mikurovim – that the holocaust will never happen again.)