I believe the lack of "on-going" contact is intentional.
I just finished reading Disney Institute's Be Our Guest, which deals with how Disney looks at Customer Service. The last section of the book was about DVC and how they set their standards.
One of the prime standards that they set for the DVC was not to become like other Timeshares in the sales process. Having a Guide calling every other week and saying "Are you ready yet" would be against DVC's customer service goals and standards.
We toured DVC, but didn't want to rush the decision. We ended up purchasing over the phone. I can't remember who my Guide was and I sure don't miss the calls. Our Guide did do a great job with the initial paperwork and arranging for our first stay.
If I need something, I know to call. That works for me.