This doesn't match my experience with that term.

My son is diagnosed with ADHD and high IQ and labeled "gifted". He's very immature, has absolutely no method, is very impulsive and can't maintain focus for more than 20 minutes. He seems very much less mature than his peers in anything.

Yet, he just understands and remembers every single thing at school much better and faster than his peers. So I guess technically that makes him "gifted" but it's not a very useful gift. It just creates problems at school because he gets bored quickly but cannot be given more work to do because he gets exhausted quickly too!

I read recently a title of an article that said "gifted children are special needs children" and that marched my experience.

I think he meant physically mature. Like the brain is more well developed.

As a former gifted child who was emotionally immature and gifted, I hope your kid gets the guidance I never did both to understand his adhd and how it impacts him, but also emotional compassion for himself and from parents about how hard adhd can be

You should consider medication. I used to be against medication, but after talking with a few of my friends who have gifted children, things like ADHD are extremely common. Avoiding medication and letting them spin in the wind is not a good strategy and it destroys their self esteem. Get as small a dose as possible and then wean him off as he gets older and hopefully his prefrontal cortex will catch up and help regulate him.