I looked up seven books written about Nikolai Berdyaev (6 in English, 1 in French), all written between 1950 and 2021 and none features the "infamous footnote". Divine and the human was published in France, where Berdyaev lived (and died), in 1947, and the quote is less remarkable in French (it's sleep rather than dream):

J’ai eu un jour la révélation de ce fait pendant le sommeil.

It's possible that people interested in Berdyaev did not care about the footnote because dreams were an important aspect in his life well featured in his writings, so him citing a dream as inspiration was not particularly remarkable. I'll let specialists of Russian philosophy confirm this - or not (I got the idea in a dream myself). Lowrie, 1960:

Another phenomenon in Berdyaev’s life was his series of mystical dreams. Many were painful and even terrifying, yet some were strangely symbolic. In the autobiography he described one recurring dream where, passing by a laden table with many guests but no place for him, he felt compelled to scramble up a nearby precipice; struggling and straining, with hands bleeding from the sharp rocks, he reached the top and came face to face with Christ hanging on His cross. In another dream he was returning to Russia, traveling alone, and there was no one else with him in the compartment. His train slowly approached the frontier. With deep emotion he pressed toward the window to catch a first glimpse of Russian soil, then suddenly, conscious of another presence, turned around to find Christ standing there. Berdyaev remarked that modern psychology tries to explain such things by invoking the subconscious. But, he added, this really “explains little and decides nothing.”

Looking up the quote itself, a TinEye search reports as the earliest instance a picture of the quote taken from Berdyaev's book and put on Twitter by an academic, Thomas A. Foster, in February 2017. It seems to have become viral after that, notably in the academic community (who needs sources if you can quote your dreams!).

Sources

• Allen, Edgar Leonard. Freedom in God : A Guide to the Thought of Nicholas Berdyaev. Folcroft Library Editions, 1973. http://archive.org/details/freedomingodguid0000alle.
• Clavet, Robert. Nicolas Berdiaeff: l’équilibre du divin et de l’humain. Médiaspaul, 1990. https://books.google.fr/books?id=seqIaJXzdqIC.
• Clarke, Oliver Fielding. Introduction To Berdyaev. Geoffrey Bles Ltd., London, 1950. http://archive.org/details/dli.ernet.13604.
• Lowrie, Donald Alexander. Rebellious Prophet; a Life of Nicolai Berdyaev. New York, Harper, 1960. http://archive.org/details/rebelliousprophe0000lowr.
• Richardson, David Bonner. Berdyaev’s Philosophy of History: An Existentialist Theory of Social Creativity and Eschatology. Springer Science & Business Media, 2012. https://books.google.fr/books/about/Berdyaev_s_Philosophy_of_History.html?id=Hn-hBQAAQBAJ.
• Spinka, Matthew. Nicolas Berdyaev: Captive of Freedom. Philadelphia: The Westminster Press, 1950. http://archive.org/details/nicolasberdyaevc0000matt.
• Tsonchev, Tsoncho. The Political Theology of Nikolai Berdyaev. The Montreal Review, 2021. https://www.academia.edu/69025478/The_Political_Theology_of_Nikolai_Berdyaev.
• Vallon, Michel Alexander. An Apostle of Freedom : Life and Teachings of Nicolas Berdyaev. New York : Philosophical Library, 1960. http://archive.org/details/apostleoffreedom0000vall_q8u8.

Edit: added the name of Nikolai Berdyaev's book, where the footnote can be found in the English edition of 1949.