I’m not sure what you’re asking exactly.
When a request comes in, they look to see if they have owners who can book that. They then send out an email to all matched owners, asking them to reply if they can make the reservation. First person to answer gets the go-ahead to book it.
Everyone else gets put back into the pool, once you reply (they want you to reply even if you don’t see the email until the next day, just to confirm you want to continue in the pool). The email tells you “ this will use 143 points, leaving 17 points left to rent”. That way, you can decide whether to say yes. I turned down some because I reckoned I would wait until a request that used at least 150 / 160 points (I also said I could borrow if necessary). But another time I accepted one even though it left me with 50points, because I (correctly) thought there would be a studio request in to use those up.
Between 7 and 11 months out, that means only home resort owners can book.
So pretty much each request is matched with owners who could book it. At 5 months, that means any owner with points still in the pool to rent.
I have no idea if they literally email everyone or just some. If the latter, I imagine they prioritise the owners who have been in the pool for the longest.
So the waitlist simply acts as a catalyst for the emails. If you were on the waitlist and someone comes in with the right number and location of points, their system would match you. They probably run that matching process each night and work from the results the next day.