I’ve seen a few scholars claim this too. I haven’t evaluated their reasoning though. But I would probably not expect homogenous beliefs 4,000 years ago. I think some of the belief might come from the names (Yahweh vs Elohim). Isn’t Elohim plural? This is not my area of expertise?
What do we make of the plural for God in Genesis? I’m not buying into it being trinitarian. The Angel of the Lord? Multiple gods?
Let us make man in our own image
He will be like one of us
Let us go and confuse their language
Or statements by God saying he will smite non existent beings?
Exodus 12:12 “On that same night I will pass through Egypt and strike down every firstborn of both people and animals, and I will bring judgment on all the gods of Egypt.
Exodus 20:3: “Thou shalt have no other gods before me.”
Is having no other Gods before me supposed to be the same thing as saying no other God’s exist?
In Exodus 32 after all the plagues, the red sea parting, God delivering them from Egypt, giving them water from a rock, when Moses in on Sinai for an extended duration, he comes down to them worshiping a golden calf:
32 When the people saw that Moses was so long in coming down from the mountain, they gathered around Aaron and said, “Come, make us gods who will go before us. As for this fellow Moses who brought us up out of Egypt, we don’t know what has happened to him.
I wonder how challenging it really would be for scholars to show monotheism developed out of former polytheistic beliefs. I’m guessing monolatry ruled the day for a while.