I recently did a lot of reading on this topic.
From what I understand, yes, once the body reaches point of type 2 it never goes back to “normal.” The cells in liver and pancreous that deal with blood sugar are destroyed over a long time of being abused. Once destroyed never regenerate. Blood sugar can be controlled with diet and excercise but those particular cells needed to deal with sugar never come back.
Remission is acheived with dedicated diet modification and excercise. But, much easier for a person to not change his life and take a pill thus the numbers are bad and getting worse every year.
Moral of the story: take care of yourself before it is too late.
I will qualify this:
I did read of a study, only the summary not the study, performed by UK NIH as I recall. They did report cases of remission if the condition was detected early enough and an extreme diet of 500 - 700 calories per day consumed until reduction of 15% - 20% of body weight was achieved.
But the key was early detection and fast massive weight loss to achieve remission.