> Just because there isn't a strict naming convention doesn't mean there isn't a longstanding convention in English-speaking countries of giving wars boring names based on the participants or theatre
That is one name that is ascribed to a conflict, but we often have many. The Forgotten War is the Korean War, The Great War is World War 1, The American Civil War had many names.
> Picking a ludicrously overblown name like "Northern Aggression" for a failed secession makes no sense in that context, but plenty of sense in Lost Cause victimhood narrative.
How is it overblown? It's a descriptive title that is certainly controversial, but if you accept that particular viewpoint, it's simply descriptive.
> Which is why it was a name popularised by 1950s segregationists, not the original secessionists who may have rejected the notion that it was a "rebellion" or "civil" war, but talked about wars of "Separation" or "War for Independence" instead.
You can certainly find its usage linked to segregationists, but the entire basis for suggesting it wasn't used before the 1950's is that people couldn't find any evidence of the term being used prior to that in their google searches. It not showing up in term searches for archived OCRed newspapers is hardly evidence that it wasn't a term used before then. Regardless, that is beside the point. You're going out of you way to project meaning into it that isn't intrinsically there.