According to Loren at Origins, CGL could always print new fiction
Why they don't do it in the last EIGHT years - is another question. As I can assume, sales of anthologies showed CGL that sales of new books to whole 400 fans aren't really pay off for himself.
All law problems knitted with a reprints of old novels which, honestly, not really needed for existing fans, because they have them all or can buy them, because thair still plenty at e-bay.