In this particular case, as with the Champagne example, the name of the product indicates its origin. Bleu d'Auvergne means "Blue from Auvergne" (a region in France), where blue is short for "blue cheese".

If someone outside of France (Auvergne, more specifically) can concoct a product with similar quality, let them label and market it under their own name.

If you fork an open source project, wouldn't it be convenient to come up with a new name for your project?