I think you'll still get a good number of people who will play just for the story. A good story is one of TES' main selling points.I like the one world concept; however, the downside of the zone scaling to CP 160 partially invalidates the majority of the quests/quest arcs. I've seen groups simply grinding to level 50, and its almost easier to knock out those levels doing it.Elder Scrolls Online is now more similar to Oblivion and Skyrim where you can go anywhere.
Pragmatically speaking, when you remove incentive to play the story arc or zone quests than players only have dungeons, trials, dailies, world bosses for gear, and Cyrodiil to do because once you're CP 160 you're at the gear cap and even then +CPs can be grinded out again until pledges, trials, and dailies reset.