I find this really deceptive. Shame on TTB (but really no surprise) for letting them label it this way.
From 27 CFR 5.22
(f) Class 6; rum. “Rum” is an alcoholic distillate from the fermented juice of sugar cane, sugar cane syrup, sugar cane molasses, or other sugar cane by-products, produced at less than 190° proof in such manner that the distillate possesses the taste, aroma, and characteristics generally attributed to rum, and bottled at not less than 80° proof; and also includes mixtures solely of such distillates.