Kids and adults DxDDP credits have always been pooled, much like QS credits are on the regular DDP. There has never been any distinction between them and they have always been interchangeable. When dining plan changes were announced by the blogs, it was stated that kids could order adult meals if they wanted, but, as Nancyg56 said, the official 2016 brochure states that children must order kid's meals if available so it doesn't appear that change is happening.