Unless you can link some actual reference, I'm going to call bullshit on this one. Dehydrated cane juice is literally just (less refined) sugar, and in my experience I have never seen a "no added sugar" label on a product with dehydrated cane juice. I actually look a lot for this because in my experience "all natural" combined with "no added sugar" almost always means Stevia, and I can't stand that stuff.

I just did a search online and all the Whole Foods soy milk I could fine listed either "organic cane sugar" as an ingredient, or was unsweetened.