The Rent/Trade Board here on the DIS does allow existing reservations to be offered. But we only allow them to be offered within 30 days of check-in date, unless the owner purchases a higher Rent/Trade Board membership level, and the owner's screen name must have been registered on the DISBoards for 6 months or longer in order to purchase one of those higher levels. So most owners here offer their points for rental, rather than an existing reservation. Recently, a new mid-tier "platinum" level was added that allows owners to post 1 existing reservation out side of the 30 day arrival window. But for the most part, currently the rental brokers will have the better selection of existing reservations especially with all the COVID point usage restrictions.