Are you asserting that it's a tradition that's not limited to Minnesota, or that it's not a tradition that exists in Minnesota?

The article itself isn't archived, it was written recently. I just included an archive link in case anyone hits a paywall on the main link. What is poorly written about it?

EDIT: Are you confusing Vietnamese egg coffee and Swedish egg coffee? They're very different things, and Swedish egg coffee is a Minnesotan tradition. The article explains how it was likely brought over by Swedish immigrants, and then died out in Sweden when filters were invented