Didn't show up in time...
My reservation didn't show up before midnight on the second night. I was unable to cancel the reservation and use the points.
As others have described here: Once the reservation shows up in your account, you can cancel it and reuse the points.
By the time our reservation did show up in MSC, the unit we wanted to reserve was long gone, and every other unit at WSJ was unavailable for our time period.
This is our first time trying out the online reservation system. It seems like our ability to reserve a week at a popular resort at 8 months is less likely now than ever before.
Probably already well discussed on this board.