I don't think it's a moot point. The Kennedy Center Honors try to stay away from controversy. This probably explains Jane Fonda not having been honored yet as well. There are still people, veterans in fact, who will never forgive her for having gone to Hanoi. Maybe enough time has passed in her case (I hope it has), but in Allen's, once Dylan and Ronan Farrow became as vocal about her abuse as they became, the issue became more of a hotbed than it had ever been. Actors won't work with him, his last film wasn't even released in the US...they would not even consider awarding him.
And I don't think he would have stayed home if he'd been selected. It isn't a competitive award, it honors one's body of work. He might have gotten a laugh out of it, but I bet the would have attended.