Sorry to disappoint but it's just a theory. A different take on that theory was put forward by Jan Assmann in 'Moses the Egyptian' which postulates that the spark for monotheism in a polytheistic system (he rather grandly called it "the Mosaic distinction") is from the cultural memory of Akhenaten's heresy. In short, the Amarna period is the first traceable instance of one God being proclaimed true and all the others false. The trauma of the Amarna period, in excising centuries old belief systems and declaring them false, left a deep scar on the collective memory of the Egyptian people. A sort of shared religious PTSD. It's this trauma that eventually leads to the evolution of monotheism in the Levant - slowly.

I personally hold little truc with this theory. It's presumptuous and almost completely lacking in contemporary evidence. Assmann was hugely criticised from every direction for this theory and is still frequently called an anti-Semite for proposing it. To his credit he is still regularly refining it, defending it and has acknowledged his own lack of nuance in its original expression. As a thought experiment it has raised some interesting ideas and certainly some of his resulting work on cultural memory/mnemohistory (whatever he's calling it these days) can lead to some untapped veins in historical discussion.

Versions of this argument have been thrown around since Sigmund Freud's Moses and Monotheism (1939) at least if not even further back. It's not very compelling. Akhenaten was so far back in time from any of the purported dates of the Exodus (which has itself been challenged pretty strongly as an event), and there's no really obvious connection between Atenism and the Israelite cult beyond monotheism.