Whirligig,
No apology was asked for. It was already given along with monetary compensation and the man whose case had gone all the way to the Supreme Court was presented with a Freedom medal by the President of the United States years later.
This to me is fascinating history! 
The point is that we can learn from mistakes made in the past. Reading through documents written by officials at the time I read some illuminating information about the mind sets at the time.
One of the questions was why they were singled out and why Germans and Italians were not rounded up and sent to camps too.  Questions about violating their civil rights as most of them had lbeen born here. 
Recognizing the contributions made by people who served or aided our troops at a time when they were treated very unfairly is important because it reminds us to to not repeat it and it's never too late to say Thank you !  The Hmong, Black Americans and Japanese-Americans all made significant contributions to our country.