I agree most likely they will require you to pay the money back and not go enlisted. However, as you know it is the needs of the AF that determine this action. I recall only a few months ago a poster stated that the AF was indeed requiring them to go enlisted.
Additionally, understand that if they come a knocking for the money it is not only the tuition, but the stipend and allowances too. You will be handed a bill and they want that money ASAP not in 2 more years when you graduate.
~ DSs friend did decide after SFT, but in Aug. as soon as he came back that this was not for him. He was handed a 43K bill AND because he was scholarship his college's bursar was notified immediately. His account was put on lock until he paid that semesters tuition bill. Thus, it was a double whammy where had had to come up with @55K in a few weeks.
~ Gojira's DS (NROTC) was handed their bill and negotiated the payback using an attorney with military law experience, the 1st negotiation was full payment. Second was 4 yrs. 3rd was 10 yrs. He owed over 100K. And yes, he is repaying with interest.
I am not saying to stay because 4 yrs ADAF military is not going to be good for your morale if you never wanted to stay. What I am saying is before you pull the ripcord talk to your folks about how you are going to find that 40-50K very quickly.
~ Personal loan, selling stock, 401K, home equity or do they have it sitting around in the bank?
Additionally, is your major something that is sought after for career opportunities once you graduate or will you need a grad degree to get hired?
Again, I am not saying stay. I am saying at this point you need to really look at the what ifs. What if they force me to go enlisted like a poster a few months ago? What if they allow me to payback, but the folks don't have the 40K or do not qualify for a personal loan, where will we find the 300-400 a month payback, plus next years tuition?
If you quit now, be prepared not only to payback everything as soon as you go back, but also be prepared for the Bursar to be informed as soon as you go back to school that AFROTC will not be paying spring semester. Most Bursars will lock your account and drop your classes within 2 weeks if you do not pay (loans or payment system). Talk to the folks because this is not only about repayment, be it enlistment or pay, it is about finding this semesters bill without the scholarship and staying at the school to finish your degree.