Wanted to bump this up to ask the same. I've got some mileage and a Go Wild! bookings coming up, have Elite Gold, and wondering I can stand by in either case for an earlier or later flight. I see some older posts saying this is possible for elites and seems it was on the website before but I don't see anything like this anymore. Previous references to stand by seem to be more than a year old. Anyone still have luck with doing these?