I don't think Rabbi Cahn made it clear in the video clip titled The Sword of Amalek and the Mystery of Purim, that Stalin was struck down with a stroke on March 1st, 1953 - which happened to be PURIM.

Here are some links with "fun facts".

https://www.jpost.com/Opinion/Purim-miracle-of-1953-483994

http://www.ministers-best-friend.com/Hitler-and-Great-Jewish-enemies-Die-on-Jewish-Holiday-of-Purim.html