That's great that you're moving him off of kibble! Well done! For kitties that struggle with the pate, we have a number of tricks to help them transition. The gravy foods are between 12-20% carbs, which is too high for diabetic cats.
And, carbs cause their numbers to be erratic and unpredictable which can make dosing and safety an issue. But fear not! It was my cats first step away from kibble too, but it needs to be a quick step, and not a place to linger. So on to the tricks for getting them to eat pate:
1. make sure you add water to the food. The pate by itself is too thick for gravy-loving cats, so adding anywhere from 1-4 tablespoons of water will help. It make take some experimenting to figure out how much water Angelo likes, so don't give up if he snubs it a few times. Oh, and make sure to mix the food and water together well. If you want to get fancy, you could use bone broth instead of water. The point is just to thin it out for them so they can lick it better. This is the first step in all of the ideas that follow below:
2. bonito flakes:
https://www.amazon.com/Kaneso-Tokuy...&pf_rd_p=71dfc2d1-518c-5342-8123-9a819de40955
You can also buy bonito flakes made for cats, but they are more expensive. And since everything about diabetes is expensive, save money when you can! To use these prepare the food with the extra water, and then put a little sprinkling of bonito flakes on top. Most cats find them irresistible. You may need to repeat this a couple of times to get through a whole can of food, but over time you can wean him off of these (at least mostly -- when you see how much he likes them you won't want to deny him the joy completely!

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3. tuna water (make sure it's tuna packed in water, not tuna packed in oil): prepare the food, and pour some tuna water over the top.
4. Parmesan cheese - same process as #2 and #3
5. Brewer's yeast or nutritional yeast. Both of these are usually sold in the bulk section of a grocery store, or in the health food section. They are different than the type of yeast you buy to make bread. They have kind of a cheesy/salty/creamy flavor, taste great on popcorn if you want to try some yourself, and my cats loooooooove it sprinkled on top of their food. Added bonus, it's high in B vitamins which are important for our kitties.
6. Fortiflora -
https://www.amazon.com/Purina-Veter...flora&qid=1554256733&s=grocery&sr=1-2-catcorr There are 30 little pouches in a box, and one pouch can last anywhere from 3 days to a week depending on how generously you sprinkle it. If you give a full pouch/day, it is a probiotic which is good for intestinal health, but it's too expensive to use that way and there are other probiotics that work better for cats. So I just use this as a flavor enhancer when my kitty gets picky about his food. You sprinkle a little like you are salting the food. Most cats would eat a shoe if you sprinkle this one it, especially if you have a cat that is coming off of kibble. It seems particularly appealing to kibble cats.