I think there was a push recently to stop listing the nutrition facts on single serve containers broken up into multiple servings because it was misleading. It really doesn't matter what you consider a serving as long as the nutrition information is accurate.
If you buy a can of coke, you're going to drink the whole thing. Same goes for a 20oz bottle. So the nutrition information on the panel should be reflective of what you're about to consume.
If you are buying a 2L its going to be broken up, so theres more leeway in how the nutrition panel can be made.