The problem is that giving up insulin at t1 is a slow and painful death, so it will be impossible to "enjoy" a year without insulin. To be honest, I'm not at all sure that a year without insulin is possible at all, usually it's a few months at best. But teenagers from well-off families rarely seriously think about suicide, at this age they often want to attract attention to themselves and can make a fatal mistake.
The crisis of adolescence is usually associated with the fact that a person realizes that not everyone around him will love him and very few people will love him simply for the fact that he exists. Diabetes is generally a great way of manipulation, so if you let a child not do something (homework, help for parents, etc.) because he has diabetes, he starts using it very quickly. This does not mean that hyperglycemia makes us feel good, but we can use it as an excuse for anything. If I didn't want to go to school as a child, I could just eat a few sweets and in the morning my bg was so high that my parents wouldn't let me go to school, but when they stopped letting me skip classes because of hyperglycemia, I stopped doing that. I understand that you are very scared for your son, but as soon as you let your fear take over, you will turn into a toy in the hands of your child. I don't know if it's help, but try not to give him positive reinforcement for his destructive behavior (a la to pay more attention and love when he feels bad) and tell him that you will love him no matter what state he is in and what he does.
At the age of 16, it is difficult to realize what death is and how much your death hurts your loved ones, but the fact that your parents are worried about you, your strength and the ability to manipulate them with the help of the disease is a pleasure. I remember we drank alcohol at that age and did a lot of dangerous things, because it seemed to us an important part of socialization. If possible, try to have your son surrounded by people with the least destructive tendencies. If his peers offend him, invite him to enroll in martial arts - the realization that you can fight back against those who offend you gives a lot, besides, it's a great outlet for aggression.