Schneider U.S.A. was the company that purchased the rights to the Goerz names and designs and some remaining inventory from Kollmorgen in the early 1970s (I believe 1972). Around that same time period, Schneider U.S.A. (now known as Schneider Optics) also became the official US distributor for Schneider lenses made by Schneider-Kreunach in Germany. At some point during the mid-1970s, the rights to the Goerz legacy products seems to have been transferred from Schneider U.S.A. to Schneider-Kreuznach. Perhaps that's why Schneider U.S.A. allowed their US trademark on the name Dagor to lapse in 1975.
In any case, Schneider-Kreuznach continued use the Dagor name on their lenses (produed under contract by Kern in Switzerland) through the mid-1980s when the 14" multicoated Dagors were manufactured.
I have no idea if Schneider-Kreuznach still owns a valid trademark on the name Dagor. However, it is interesting that the new 550mm Fine Art XXL lens is a Dagor type construction (6/2), but they chose not to use the name Dagor for this product.