Just read this on reddit:
"If you're a coach with a job offer you haven't decided on yet, are you obligated to disclose that to recruits?" If you do tell them and you don't take the job, you've shot yourself in the foot and lost a big time recruit. If you do tell them and you do take the job, you've pissed off your previous employer and burned a bridge for the future of your career. If you don't tell him and you do take the job, you've fucked over the player and it's shitty.If you don't tell him and you don't take the job, no one was wronged and no one ever needs to know.
I know it absolutely stinks for a recruit or newly signed player for a coach to leave. However, because of the crazy fluidity and uncertainty surrounding job changes, it's almost impossible for a coach to tell the departing team before the ink is dry. The shady part to me, though, is if a coach is already recruiting for his new team before officially leaving his previous team.