Covid induced T1 diabetes

There was some talk on the news about Covid causing temporary blood glucose problems, but not real T1 diabetes.
So if he's got T1, then there is no going back...

He'll have to learn to live with it, some find it easier to control than the others, but it is possible to lead a normal life and do whatever you like. Some education and effort is needed especially when starting out and one should take it seriously...

I had my first Covid vaccine a few months after my T1 diagnosis. If it was the other way around, I'd probably blame the vaccine for T1...
Same with Covid.
Good luck with everything.

I'm afraid I cannot offer any "good" news, or hope for a reversal.

While I can't be certain, It's highly likely that Covid triggered, or increased the rate at which I developed T1 diabetes. I was diagnosed at the end of June this year, eight days into a covid infection. Like your brother, I was admitted to ICU for 5 days.

Things were tough at the beginning, I won't lie. I struggled with accepting my diagnosis until I received my antibody results confirming the T1 diagnosis. These results really helped me accept my diagnosis. Hopefully, your brother is being tested for antibodies to confirm his T1 diagnosis.

I'd suggest you both avoid reading articles about the link between COVID and diabetes. I did this, and it personally delayed me accepting my new way of life, and offered me false hope at a time where I was overwhelmed with everything else I needed to learn about managing my diabetes.

Encourage your brother to talk with the healthcare team working with him if he struggles to process his diagnosis and his time at hospital. They can help. And, most importantly, make sure that your brother knows that he isn't alone, it will get better, and his diagnosis doesn't stop him doing the things he enjoys.