The cable companies can use the existing fiber on the poles if they have dark fiber which is always available for rolls and protection. The way Verizon is using theirs is by using a few fibers to split and feed the FDH for splitting to the houses on feeder fiber. It doesnt take alot of fiber to distribute DWDM.
This is CABL.com posting #142165. Tiny Link: cabl.co/mK89