If the rooms you want are booked before the seven month window even opens, the way they are going to open after that are two ways.
1) BLT owners who has a room booked decided to switch resorts. This happens, but generally those rooms are snapped up the other direction pretty much simultaneously.
2) People with rooms booked who decide to cancel. Those rooms will get taken by the waitlist.
No additional inventory is added at seven months.
Its possible that someone will be able to sneak in with a reservation when someone switches or someone cancels before its rebooked during a switch or taken by the waitlist. But you are going to need to be darn lucky. If you were an owner, willing to call every day, you might have some luck, but as a renter, finding an owner willing to spend that time - I wouldn't hold out hope.