It could but to be honest, the average buyer of DVC...outside of these boards...don't even realize things about resale and don't buy with the mindset of selling and getting there money back. So, I just don't think DVD cares that much about it in the long run.
As long as they can maintain sales at a healthy level...and that level may be less than years prior...they will put in things that make the direct purchase more attractive. The parks are what drive the DVC product (even though we don't buy for parks) so as long as those exist, there will be a DVC buyer out there.