I think maybe Kevin Moore takes himself too seriously. Though I absolutely love all his DT work, as well as Chroma Key, OSI, Ghostbook and whatnot, I think making an appearance with DT for a night would be a great gesture.
I don't get the impression there is any real bad blood. And going your own way doesnt have to mean ignoring your previous work. It can simply be about revisiting the material with a different mindset or perspective, for himself, the band, and mostly the fans.
Obisously Kevin Moore had some good times with DT and helped create some great music with them. Why not take the opportunity to celebrate the music and memories he helped make? It's not like he's out touring that often, and I, for one, would love to see him, in any capacity.