Booked a week in February at Riviera, decided a month later to add on an extra day but no availability. I added a single day waitlist at the end, hoping if I got it I could call and they could combine the reservation. Weeks go by, nothing. I happened to check today, waitlist still sitting there but the day I'm looking for has availability. I modify my existing reservation and get the extra day. Why didn't the waitlist work? I checked my email, no notification at all. Does it work differently than I think it does?