Does the from concentrate stuff have anything different other than some water removed? One you add water back in isn't it the same as the not from concentrate stuff? I.e. Still the same 4-6 oranges no matter what?
It's the same 4-6 oranges if you consider having a sterilized orange juice concentrate spend 6 months to a year in storage and lose all of it's flavor "the same" as a freshly squeezed orange.
For most commercial orange juices, all the flavor is engineered with artificial ingredients. I'm pretty sure that the only reason they still bother with oranges is legal requirements.