My son just found out in the last couple of days what his new squadron will be. I believe that basically the only say so you have is if you are a legacy. (Or if you have a problem with certain squadron personnel, which you don't want to have). So yes, you stay with the new squadron for the next 3 years. And part of that is to teach you about working/leading a squadron. You'll start getting squadron jobs and enlisted ranks; then officer ranks. You'll be working at the squadron, group, and wing levels. You need to keep people together for 3 years to have effective training in those areas. The 4th year cadet has too many variables. It's easier to move them from BCT to cadet in the same squadron. This way those you made it through 6 weeks of BCT with, can be part of your support system for the next 6-7 months until recognition.
After that, you get to "experience" what it's like to "PCS" (Permanent Change of Station). You get a new squadron. New people. New leadership. Build New Pride. etc.... Part of the academy's training is to simulate the real Air force. Like I said; you "BECOME" enlisted grades. You'll then become officer grades. You'll perform similar duties to those of the people you will some day lead. You'll change squadron's after the 1st year just like you will have to do in the future. (Trivia Military History: I'll look up a source later; but PCS'ing developed basically during the roman empire time. "Might have been earlier, but I think Roman". Purpose was for the soldier to NOT GET EMOTIONALLY ATTACHED to the local community and it's people. When a war would start, they didn't want the soldiers to refuse to go off and fight because they wanted to STAY and protect THEIR COMMUNITY and families. So, don't let them have a family or emotional ties.)
Anyway; part of military life is to PCS. New squadron, new leaders, new friends, new commander, new dorm, etc... And a normal PCS (When budget cuts aren't kicking in) are anywhere from 2-4 years. So playing "Real" military is one of the reasons for the squadron changes. later.... mike....