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.
It was several years ago. I brought it home to my wife (the soy milk drinker in the household) and though I had a laugh, she was not amused.
I get frustrated too. I avoid aspartame/sucralose/etc... then it turns out they have stevia/monk fruit extract/etc
oh, and there are some other ones that you might want to avoid.
A low FODMAP diet would cut out not only fructose, but lactose and the -itols like sorbitol, xylitol, and mannitol