I would change that to "can sometimes be fixed" as type 2 diabetes can damage the pancreas (and other organs) to the point that "proper diet and some exercise" alone will not rejuvenate them.
I guess my point is that once you figure out that you need to bandaid the problem by giving yourself insulin, it can be fixed. Honestly when it gets to that point the doctor should be telling you that you need to reverse course asap.
I don't think many (any?) type 2 diabetics have artificial pancreases. Also, even with good glucose control, type 2 diabetes still seems to lead to some pretty bad comorbidities.
