Producing new courses is a lot harder and time consuming than producing Best Of courses from what they already have.
New hole placements require making a ton more photographs, post production of the photographs, and the time needed to integrate the new holes into the programming. Before that can happen WGT would have to get the golf course to let WGT return and disrupt their operation to make the needed photographs.
It takes WGT's team of photographers a couple of weeks to make the 200,000 to 300,000 photographs it takes to produce all 18 holes of a golf course. We can speculate on how much more time and photographs it would take to photograph and post process more hole placements per green.