Not quite. If you're applying for a pilot slot when applying to OTS then it's just that - you either get selected for it or you don't. It works that way on all the "rated" boards (pilot, nav, abm - i.e. flying jobs).
"Non-rated" boards (i.e. non-flying jobs) work the way in which you describe; where you get selected first, and then they assign you a job.
EDIT: for clarity