Also more lifting surface................
Honestly I’m not sure about that, looking at those, what I assume are rendering, not convinced the surface area of the wing is that much bigger, bit it does look a hell of a lot thinner.
Larger surface area would generate more lift, but I don’t know if it would reduce drag/improve fuel efficiency... Unless you were to fly slower because the increased surface would certainly provide the same lift and a slower speed... but I don’t think the airlines want to reduce their speed much... Seems that would be a tradeoff they would not want to make.