Keep in mind that each resort allows only a certain number of owners, basically enough to cover about 96% of the resort. Don't think of it like airlines where they overbook passengers. The resorts are there and it's just a matter of balancing guest's stays with rooms. That's why at home resorts, at 8+ months, there should never be a problem with low or mid-season ressies.
At 7-months, others can book into any resort. So if you own at BWV but want VWL, and get it, then that leaves your BWV available for maybe an OKW owner, etc. It's really a balancing act.
Plan ahead and you shouldn't have any problems.