It's not marketing hype, it's what they have to do if they want to have factory rifles and factory ammo that works together for long range shooting. Hornady's formula is to partner with rifle manufactures and offer factory solutions for long range shooting. They can't load factory 6.5x284 and make it work in a factory gun, their isn't a standard saami spec. Should they load it at 2.8" oal so it will fit in standard short actions or should they load it long so you have to use a long action? Should they use the Norma spec or the Win spec. Wait, does any manufacturer chamber factory rifles in 6.5x284? It would never work, there are to many variables that they can't control.
But, if Hornady makes a new round they can set the spec so it will work with long bullets and make sure the rifles are built with fast enough twists to accommodate the long bullets. Now a guy can buy a new rifle off the shelf, get a box of bullets over the counter and go hit steel at a thousand yards. It's that simple, they're bringing long range shooting to the masses.