Before we begin, it's always important to note disclaimers when reading health and diet books.
This will be brief. In the previous 2012 version of ISWF you were not allowed to consume white potatoes or table salt.
White potatoes had been previously excluded “because people like to eat them in the form of fries and chips.” The Hartwig’s admitted their exclusion was pretty arbitrary and that potatoes are nutrient dense veggies. They do suggest that you should limit your intake if you are “metabolically challenged, and not very active” as potatoes contain a lot of energy. They could have added that this also applies to sweet potatoes too, as both types of potatoes contain the same amount of carbohydrate per 100 gram serving. [1,2]
For more reading on the differences between sweet and regular potatoes, check out the below article at Precision Nutrition.
Some of the Whole30 followers had pointed out that “technically, basic table salt wasn’t allowed on the program because it’s always stabilized with dextrose”. They now allow table salt and advise you to switch between table and sea salt.
There is nothing to worry about in terms of food safety with added dextrose in food. When added to salt, it helps keep it shelf stable for a long time which can lead to decreased food waste. Dextrose is merely a form of glucose, the dextrorotatory form of glucose to be exact, and is the “predominant naturally occurring form”.  I'm not sure if it was technically banned from the program before but if it was, that is just odd.
That’s it. Told you this would be short.