Yes, that's correct. Dental floss with "no mint and has a natural Cinnamon Flavor and it is completely free of all animal source ingredients" is being pushed by at least one company.
Use of dental floss with waxed silken thread came about in about 1819, but the use of dental floss was not common because silken thread was too expensive. During World War II, Dupont began using nylon and it replaced silk as the new material for many products, including dental floss. Of course, there are resin-coated nylon and teflon coated floss, but they do not use animal parts either. Not sure what kind of "animal source ingredients" are found in synthetic materials..