This may be more of an IP issue than a publisher issue. I worked editing another (non-RPG) project that was Star Wars and asked why we didn't have our artists (who were under my employ and were very talented) draw up scenes from the text. Apparently that would mean that we would have to wait for the next meeting of LucasFilm Story Group to convene (no date given, no contact info given after numerous phone calls to agents) and submit a detailed reasoning about why this should be canon (about 5 pages long) that they would decide on. We couldn't actually submit the pictures, only words about the pictures.

FFG might have a better deal with Disney and LucasFilm, but imo, they are a company that is all about their red tape.