Can diabetes be completely reversed/cured as if it never happened?

Type 1 - no.  An autoimmune disorder causes the pancreas to completely stop producing insulin.  No cure has been found yet.  Type 1 always needs insulin injections.

Type 2 - no.  There is no "cure" that makes it as though it never happened.  Some people can avoid medication by changing the risks that have caused the issue.  Risk factors include poor diet, lack of exercise, obesity, heredity, and age.  (there are other risks - but these are the most common.)  If the reason a person is becoming diabetic is because of poor diet, lack of exercise, and obesity - then they may be able to reverse the problem by eating better - getting more exercise - and dropping weight.  If they return to their old habits - the problem will come back because it is not actually cured - it was stopped and controlled by the changes that they made.  If they return to old, bad habits, then the diabetes would return.  If heredity or age is why it is happening, then there isn't very much that would change or reverse it.  They might be able to slow it with good habits, but it would still happen.  

If it can happen, no one has come forward with the method/protocol/steps, that makes it a reality for every diabetic that has followed them.

The person or group that comes up with such a method, will become famous and rich overnight. 

Type 1 diabetes cannot be cured. It is a chronic autoimmune disease. There is no remission. While some type 1 diabetics are insulin resistant, some are not. I am pretty insulin sensitive after over 65 years and counting. The strep infection that gave me Roselle?when I was a year and 8 months old caused my immune system to destroy the insulin producing beta cells in my pancreas. 

One of my great grandmother's was a full Cherokee. One of my my mother's cousins developed Type 2 diabetes in her late 50s. 

Type 2 diabetes is almost a different disease. It is genetic and/ or lifestyle. To a certain extent it may be reversible, but it is also chronic disease.

That ignores gestational and other types of diabetes. They are?also incurable. Any diabetes cure is going to have to be customized and tailored to each diabetic. Each diabetic is unique. 

Diabetes is a genetic disorder that causes the pancreas to stop being able to trigger proper insulin (a hormone) that helps transport glucose throughout the body. 

Once the pancreas has failed, there's no going back. 

Diabetes II is not really diabetes but rather a metabolic disorder brought on by a poor diet in 98% of cases.   

Diabetes II is 99.99% preventable and NASCENT diabetes II CAN be reversed by a relatively simple set of dietary changes.

Simply eating only whole foods and drinking only water, unsweetened teas and unflavored milk will PREVENT nearly all diabetes II and even reverse it in the first six months after onset.

Half of sugar is fructose and fructose,  when consumed regularly without mitigation (insoluble fiber) results in a build-up of toxins (ROS) in the hepatic cell's mitochondria, causing inflammation,  which begets MORE inflammation,  which begets MORE inflammation and so on.

The inflammation causes liver dysfunction that typically starts out with excess body fat/obesity (but not all cases), adult acne and IBS.  As it progresses,  the liver attempts to 'spread the pain' to other organs,  causing organs to become dysfunctional and ultimately fail.

When the CV system fails first,  we call it heart disease. 

When the ovaries become dysfunctional,  it's PCOS.

When it's the pancreas that gives, we call it diabetes II.   It was named long before the mechanism was known,  and it's symptoms mirror diabetes',  but they're not at all related. 

I hope this is professional enough;)

i think if you have prediabetes it might be able to get reversed

It is possible, depending on the type and severity. I don't think you can cure it but reverse it. If it is genetic, probably not. If you are very serious about changing lifestyle habits, and strictly follow procedure, it has been known to reverse for some people. Not to say there couldn't be any lingering damage afterwards though 

🥴 Yes.

Ive seen it. 

However.... this person barely ate for 4 years. Most of the time she starved herself.

That can be dangerous for diabetics. If your sugar is too high or low you can fall into a diabetic coma.