You might be surprised to see how many peanut butter brands have sugar in them. Jif is essentially peanut butter mixed with lard, (they use hydrogenated vege oil to keep it meat free now), to make it solid at room temperature. It also has some sugar in it. From the company website:
So I'm not surprised to find artificial sweeteners replacing the high fructose corn syrup and/or sugar in some peanut butters.
There is sugar of some kind in all sorts of products. I have to work hard to avoid it because it's just not necessary for everything I eat to be sweet.
I know peanut butters have sugar or HFCS in them, I just would not expect to see xylitol in them given it is an artificial sweetener and a rather exotic one at that. Practically all processed food has sugar, HFCS* or both any more.
I guess I would be surprised to see regular products with artificial sweeteners of any kind rather than HFCS. I would expect ones with artificial sweeteners replacing HFCS to be touted as "diet" peanut butters.
Technically xylitol is not artificial, since it is usually birch derived sweetener I thought it was.
I think I'd be more surprised if peanut butter did not have added oil. It's been long enough I didn't realize that some used hydrogenated oils or animal based fats. Personally, I think I'd rather have the lard.
The problem with labeling, it is possible for, say, sugar free yogurt to have enough extra fat to be as high in calories as regular. Same situation with fat free yogurt but with extra sweeteners.
Gotta read those labels. And understand when an individual package is not an individual serving.
*High Fructose Corn Syrup