While I agree with M. Heiser that there is a Divine Council, I don’t see it everywhere he does, including here. Men were called “the sons of God” before the Babylonian captivity. I wonder if it is not counting the 70 descendants of Noah as the “sons of God” here as a distinguished form of address for the inheritors of the covenant.
To be a double spoilsport, the language in chapters nine and ten where it says “by these were the nations divided” doesn’t really mean a situation where they were the physical ancestors of everyone in the new nation. More like their large personal households with many servants and hangers-on became the core of new nations.