Complex sentence: Although Amtrak has retired its sleeping cars that were built with drawing rooms, they are still used by Via Rail Canada; the traditional nomenclature is seen as archaic, so they are officially marketed as "triple bedrooms".
Split into simpler sentences: Although Amtrak has retired its sleeping cars that were built with drawing rooms, they are still used by Via Rail Canada. The traditional nomenclature is seen as archaic, hence they are marketed as "triple bedrooms".