AFAIK, there is no standby for INTL flights. So changing to the more direct routing would involve either a very friendly ticket agent or a change fee. While I agree it'd be nice to have that happen, I'd prepare for that not happening and instead sticking with the tickets as booked or paying a change fee ($250 on INTL) + fare difference if you really want to change. Things could change if your current flights are seriously overbooked, but I think that the odds of that could be slim. Just be prepared to fly on the itinerary that you paid for.