It's just a guideline, I wouldn't sweat the details. You could always try for 125-135g of carbs with 25-35g of fiber in there and if you want to tweak it further than you can cut the non-fiber carbs further to hit that total 100g mark or lower. The point of the article is essentially to give a rough number of a daily carb target that allows you to lose fat while still not going keto or necessarily losing energy in the gym as usual with extremely low carb diets. Consider 100g the sweet spot, so to speak.
What are you goals? If you're training, remember the golden rule: nutrient timing. IMO this is as important as what you are ingesting. Center carbs around your workout if you are eating less so you aren't dragging in the gym. Personally I have nothing but amazing things to say about Plazma for your workouts and I am around 100g a day of carbs INCLUDING Plazma. If you're already pretty lean then you are going to be more tactical with your nutrition, but if you aren't lean (like me!) then worry more about hitting some basic numbers (like the 100g carb recommendation and at least 1g of protein per pound of bodyweight) while centering those carbs around your workout and don't worry about the small stuff.
FYI, not all carbs are sugar and fiber and IMO if you are cutting and worried about your carb intake, I would cut virtually all sugar out to begin with outside of cheat meals (which is a whole other debatable topic lol).
Just reread the article, looks like their example says to INCLUDE fiber into the 100g total, but again, the point of the article IMO isn't the exact numbers but rather the concept.