There’s more information about that upcoming Chess concert in this interview.
He, apparently, had been trying to tell Tim [Rice] that he has discovered a way that he thinks [Chess] makes sense… He had found a way to present it—cutting and pasting, doing certain things differently, making different choices, adding lyrics, making it all through-sung—and one of the choices that he has made is to present it with this casting.
At first it sounded like this thing was going to be mostly a concert version of the concept album, but this makes it sound more like yet another rewrite attempt that happens to be particularly inspired by the concept album, which I’m not sure is really that revolutionary of an idea. Everyone thinks they know how to fix Chess. Some do a better job than others, so we’ll see what happens, I guess.