There is no way to know 100% for sure.
Game availability is not in real time, it is only an estimate of GF's entire stock. Even though a game may be listed as "Available Now" or "High", that may not be entirely accurate.
While the game might be available at one distribution center, it may not be available from the center your games are shipped from. In that case you are sent the first available title in your GameQ that can be sent from your distribution center.
Good luck and good gaming.