I agree both you and the parent, I don't think you're disagreeing, you're just talking about different things. You're talking about the historical distinction, the parent is talking about how things are nowadays.[0]

I found the article a bit disingenuous since you need to know what the Uerdingen line is and its context to understand what they're saying, since the divide isn't quite what it used to be.

[0]: http://www.atlas-alltagssprache.de/runde-2/f25c/