This is literally a "my two cents' worth" answer from Gemini Pro. It's a straightforward inference from the fact that "Anno Mundi" means "in the year of the world", thus especially in the "year since creation", and that the main text references Abraham's birth with conflicting dates. It's nifty that we now have automated means of extracting a sensible scholarly consensus of "what could this possibly mean" but there's absolutely no mystery here.