Robert Mondavi “invented” Fumé Blanc because he wanted to

Robert Mondavi Winery Fume Blanc
distinguish the high-quality Sauvignon Blanc he was making in the French-style from the other California Sauvignon Blanc that was widely viewed as ordinary “run of the mill” sweet wines. Mondavi realized that changing the name wouldn’t be enough to change people’s idea of California Sauvignon Blanc so he decided to age it in oak barrels. His bold move to rename his dry-fermented barrel-aged wine Fumé Blanc quickly paid off as demand for this “new” wine grew in California and across the United States. Mondavi’s decision not to trademark the name was a stroke of brilliance on his part because more people could use the name and by doing so increase its name recognition and acceptance worldwide. The name Fumé Blanc is commonly associated with oak-aged Sauvignon Blanc made in the United States since the late1960’s. Robert Mondavi never intended to imply that Fumé Blanc was a specific style or method of making wine but only a name for his wine. There is nothing that dictates Fumé Blanc must be oak-aged. You can find Fumé Blanc that is not aged in oak and that is perfectly acceptable because under current U.S. law the terms “Sauvignon Blanc” and “Fumé Blanc” are synonymous.
If you are curious I suggest you try Fumé Blanc from the winery

Robert Mondavi Winery Fume Blanc
that started it all, the Robert Mondavi Winery. 2017 Fumé Blanc Napa Valley from Robert Mondavi Winery has aromas of peach, citrus and of course, smoke followed by crisp acidity and flavors of pear, citrus, and vanilla/buttery oak.
The wine world is full of interesting stories like this and others where you may find yourself asking is it “Lemberger” or “Blaufränkisch”? Don’t even get me started with the marketing genius behind the “Syrah” or “Shiraz” campaign.LOL My advice is to ignore the marketing hype and drink what you like no matter what is printed on the label.