I'm basing what I'm saying there purely on experience. I don't see anything documented about this scenario either. And while I've used AD Groups in client deployments, I have not been in the situation where that AD group has moved.
In short, I'm guessing here, but knowing what I know about the application, I'm doubtful that there's anything in there that would automatically (1) periodically validate the AD Groups that you have set up, and (2) search for the new location of that group and repoint it. I'm quite certain that this new (relatively) feature in DLP isn't advanced to the point where it would do this.
So take my comment with a grain of salt, but I'd be willing to place a bet that your only recourse here is to reconfigure the group manually if it moves. I've been working with DLP since 2006 (ex Vontu, ex SYMC services), so have a pretty good feel for these things if that helps. Other than that, I'd say to open a case with Support for the question and get the "official" answer. Sorry I don't have a definitive answer to give you here.
~Keith