I've been watching
DVC build resorts for 15 years now. And I've been watching Disney as a company execute for 30. And I've been watching this board for the 15 I've been watching DVC.
DVC is highly unlikely to build a resort with a waterpark attached - although members here will get really excited about the possible rumor.
Regarding this conversation - Disney is very unlikely to do it, and therefore its unlikely that there will be a significant change to BLT seven month availability. DVC has been in two modes
1) Build small resorts attached to existing Deluxes. The size of these resorts tend to be small enough that their effect on the overall patterns of availability has been - from watching for fifteen years - negligible. BLT, which was a rather large build for "attached to a Deluxe" didn't change booking patterns at the in demand BCV appreciatively - they are still as hard to get as pre-BLT.
2) Build larger resorts where land is available and infrastructure is easy to run (SSR, VAKL-Kidani). But don't make them so much more attractive that their desirability creates balance in the system (i.e. there was a lot of talk about a waterpark at SSR because it would be so big that it would need such an attraction to create system balance). These resorts are big enough to have a negative impact.
DVC has no interest in system balance - they don't care if its harder next year to get BCV during Food and Wine at seven months than it was this year. Or if I'm never able to book a BLT standard view room as a non-owner. They are interested in spending minimum capital to get maximum sales as quickly as they can. That strategy does not bode well for waterparks attached to DVC resorts.