Yeah I also disagree with code changes here. This thread went in an unexpected direction since I last poked my head in :)
My thought is just in docs I would de-emphasize the mathy part of this. We can say a DAG is airflow's model for a collection of tasks that run, typically on a schedule. We could say further add, e.g. in *one place* somewhere, that the name DAG originated from a mathematical concept called directed acyclic graph. But I do not think we need to go revising history about that and providing new words for the acronym. But it has always been the reality that an Airflow DAG is strictly speaking a directed acyclic graph. It's something different. We do forbid cycles. And it does contain the info needed to construct a graph of the tasks. But it's much richer than that concept as well. I don't think we really need to go much further than that. But I'd also be in support of writing `dag` or `dags` in docs instead of DAG or DAGs because it's ugly to do so, and unnecessary, and it invokes that mathy concept that is both confusing and inadequate.
