I would agree that it may be the soil and climate that produce whatever it is that makes a Cuban cigar a Cuban cigar.
San Marzano tomatoes are highly prized for their flavor but unless they are grown in the volcanic soil in what I'll assume is San Marzano Italy they are not the same. I grew them one year, no big deal. Same with Vidalia onions, I believe they are a Granex variety but unless grown in the low sulfur soil of Vadalia county Georgia they won't taste the same. Seems it would be the same for Cuban cigars.