As mentioned, dry diets create a state of chronic dehydration for the cat that can cause other nutrition related ailments like kidney disease and urinary tract disease. Cats evolved in the desert and need moisture from their food, as their thirst drives do not compensate for dry diets.
The other problem with low carb dry foods is that many diabetic cats cannot tolerate the way carbs are presented in dry food, even if it's below 10%. Because of the way it's manufactured, dry food must use a starch to bind the food together, and starches are problematic for diabetics. For example, the food you're recommending uses Potato Starch as a binder. Potatoes are a highly glycemic vegetable.
Also, I don't believe the manufacturer's claims that the food is zero % carbs--there's no way a food can contain potato starch as the 4th ingredient and have no carbohydrate content. The aren't calculating the carb content per 100/kcal which is very misleading.
But, I'm very glad that you're so caring for diabetic cats! There's a ton of knowledge here, so I'm glad you made it to the message boards.