There's nothing on their site, so I e-mailed the question; but I did find news stories about it.
The US Department of Agriculture made the controversial decision last year, but it only came to light last week during the course of a court case in Texas.
http://www.sun-sentinel.com/news/local/southflorida/sfl-afries15jun15%2C0%2C202707.story?coll=sfla-home-headlines
The USDA quietly changed the regulations last year at the behest of the french fry industry, which has spent the past five decades pushing for a revision to the Perishable Agricultural Commodities Act (PACA). The law was passed by Congress in 1930 to protect fruit and vegetable farmers in the event that their customers went out of business without paying for their produce.
"This is something that only lawyers could do," Elliott said, pointing to a stack of legal documents debating the French fry change. "There must be 100 pages there about something you could summarize in one paragraph: Batter-coated French fries are not fresh vegetables."
Meir Stampfer, a professor of nutrition at the Harvard School of Public Health, said it "boggles the mind" that the USDA would label French fries a fresh vegetable since most commercial fries are prepared in oil laden with heart-clogging trans-fat.
http://www.commondreams.org/headlines04/0615-02.htm
The french fry rule calls to mind the USDA's attempt in 1981 to classify ketchup and pickle relish as vegetables, an idea that was dropped amid public protests.