There are "back channels" for european unpasteurized cheese to be sold here. I've been friends with a couple of cheesemongers who sell that stuff. I asked them how it comes over here when the FDA doesn't allow it. "In shipping containers, like everything else". I asked them what would happen if it was discovered. "They'd probably just destroy it all." I've found examples of such cheeses in great cheese stores across the USA.
A food product is much more a sum of ingredients and procedure to process them, than just something something looking/tasting similar from given country. Especially those protected as historically significant to given place.
So no, what you buy as brie, if it went through official US import channels, is not real Brie. Now how much is the real difference in taste is another topic, but we take protecting traditional methods of making these things very seriously here in Europe. Very anti-race-to-the-bottom approach.
It was probably a reference to Brie de Meaux, which is a type of brie that only comes from France and is (I believe) illegal to import in the United States.