Personally, I think that Cabo wasn't as well received as WGT had hoped. I think a stumbling block must have been hit somewhere.
A post by a WGT Admin (can't remember which one) said that we'd be getting a new TruGolf course every couple of months. It's been roughly five months since Cabo was released.
And it's not like it takes the same processing time as a WGT course - the E6 library (which includes Cabo) has over 70 courses currently in there. http://www.trugolf.com/golf_simulator/software/e6golf/index.php
Unless a new course is released in the coming update, TruGolf courses may well be as rare as WGT ones. It is even possible, in my opinion, that we won't get another one.
Jack.