There are many questions, should the tube map only cover the central zones, should it only cover the tube, should it be a larger format?
I believe if these questions were asked, the answer, the way things are going would be, let’s just not bother producing a printed map at all. So maybe we should keep what we’ve got.
Personally, I’d redraw the map starting with Elizabeth and Thameslink as straight lines and remove the non core part of Thameslink. Possibly change it to a larger format, and the larger format would allow space for a big advert on the back which would help pay for it