Moffet wrote that original story so he is just continuing it now since he is the big cheese.
He may have wrote Silence, but I doubt at that point he had thought there would be a new Doctor with new companions to tie into River's first appearance.
I am interested to see where they are going with it. I am wondering if they are going to go with obvious answer to who was in the spacesuit in the first episode or go a different way.