Is it true that diabetes never goes away even if you lose all the weight you need to?

Semantics: Best to always consider yourself a diabetic once the diagnosis has been made, even if healthy lifestyle changes has normalized your blood sugars. Reason is, there's still some underlying pancreatic dysfunction and identifying yourself as a diabetic will help reinforce the continued need for healthy choices.

Technically yes: You may no longer need medications once you lose weight, but some of the metabolic defects will remain, so if you stop being careful, the blood sugars will go back up.