I doubt -- wish you all the luck, but AA will not recognize your status until the computer process your trip. In my personal experience it takes from 2 to 4 days to register. Never in my account I saw an Int'l trip accounted by the following day.

However, in your case, I don't see any other benefit that get ahead on the upgrade stand-by list from other Platinums -- which you probably are now since you request your upgrade so far in advance. Become AA EXP overnight, will not put you ahead of all the other EXP that are already in the list.

Good Luck!