I don't believe that is correct. The sworn oath comes prior to basic training.
There is a sworn oath before basic. But the sworn oath at the end of basic is the binding one. Up until the end of basic you or the military can say, get out. No ucmj issues. Sign here and go. After basic it’s a court marshal, ucmj event. Ever heard of a basic trainee being court martialled? At basic they are instructed and tested on all aspects of military life. UCMJ, appearance, etc. Only after they have received that training can they be held accountable to those standards.
I had to sear the oath at the induction center.