It sounds like you guys are actually being assigned a "side" earlier than in previous classes. When I got the email confirming my class date in May of this year, they asked which side we preferred, but no one actually ended up with a choice. They assigned guys living in PHL to AA and others who live in DFW and LAX got US.

We found out just a few days before class if we were assigned to AA or US. Hopefully they've switched it to allow more people to choose what works best for them.