You know, I think this is just a case of the wrong words being used.
If your cat had BG that was hyperglycemic for 2 weeks, then maybe that's all it was - high blood glucose readings. It doesn't mean it was "diabetes". If that is the case, then your cats higher bg numbers could very well have gone back down to normal levels. Especially if the diabetes diagnosis was NOT verified by using a fruct test or urinalysis.
But no matter what your vet says, or what you choose to believe, if a cat is correctly diagnosed with "feline diabetes" then he's that way for the rest of his life, period. Diabetes doesn't just "go away". If you read the information I quoted above, it says that very plainly. If he had diabetes, then he will remain that way. Saying over and over again that "it's just not true" doesn't make it "not true".
Certainly, cats whose diabetes seems to have resolved should be considered to be susceptible to a recurrence of their clinical diabetes, and it would be important to avoid the circumstances that could promote a return to the diabetic state. That would include avoiding any medications known to antagonize the effectiveness of insulin, such as glucocorticoids and progestins, maintaining ideal body weight, and minimizing concurrent illnesses.
And Julia is 100% correct. If you wait until you see physical signs of diabetes, when you could have discovered the disease was present much sooner by doing a simple blood test, then that's just pointless and not good for your cat, and it does damage to his body. The earlier you catch diabetes, the better the chances that a cat will go into remission. Unless and until your kitty has BG levels in "normal range" for 2 weeks, he isn't "in remission". We didn't make that up. It's according to published studies.
I understand that your vet is your friend from high school, and that you trust his opinion very much. If you can't trust your vet's opinion and advice, then there's no point in doing business with them because it's just flushing your money down the toilet. We have provided multiple links to actual studies and data. If your vet has published data and studies that says the opposite of what we are saying, then please share them with us. Maybe we can all learn something together.
My cat has been on low carb canned food for years. He is on the Hill's Rx food now, which I will definitely be discussing with my vet. He is not overweight and never has been. I don't think diet played a role in any of this.
You might be right, and it wasn't diet that played any role. But Hill's Rx food is junk, and the fact that most vets don't know that or won't admit that is criminal. And Hill's doesn't make a "low carb" food.
Also, a cat doesn't have to have been, or be, overweight to get diabetes. Every cat I have ever been blessed with, prior to Bob getting diabetes, ate the same food. Mostly dry, and rarely low carb canned. I've had fat cats, skinny cats, a couple of obese ones. They've died from just about everything from getting hit be a car, to cancer, to just plain old age. Yet Bob is the only one whoever got diabetes. It just happens, there aren't any guarantees that it will or it won't. But now that I know what is the best diet for any cat, I will never subject any cat I own in the future to high carbs or dry food, because it's the wrong thing to do.
The pancreatitis could be what's behind the high readings, and now that the pancreatitis has been treated, the numbers are back to normal. But if the pancreas has been damaged, or future flare ups of pancreatitis happen, then his ability to produce insulin may be adversely affected, in which case the high numbers will return, and might stick around next time.
What people are trying to do is convince you to be proactive. We all know how much is sucks to have to deal with treating a diabetic cat. I only had to do it for 10 weeks but I sure don't want to have to do it again. Some of us have been dealing with FD for years so we understand how much goes into it, and most importantly we understand how horrible it is for the cat to be an uncontrolled or undiagnosed diabetic. We're trying to help you avoid that, for you, and for kitty.
Carl