I think never is a strong general term in this situation. Especially with position coaches. The DL coach and the DL are together a lot over the course of a season, the WR coach and the WR, etc. Those rooms are where the relationships and bonds actually occur. I've seen it where players know it is coming and some coaches can be transparent about it to a degree until things are final one way or the other.
The most perfect "way to do it" is to be fucking human and communicate, which we seem to have forgotten how to do as a society and this profession in general has sucked at it for longer than the rest of the mainstream public. I think what IrishLax said is precisely the perfect way to do it. Make an effort to communicate what is happening and thank the players for their efforts. Maybe even open the floor to questions. At that point, you've done all you can do and if feelings are hurt, so it goes. Kids are resilient and tend to get over things, especially college athletes who at that point have learned a few life lessons and have probably overcome some level of adversity.
Jedd Fisch left Arizona in pretty shitty fashion. The "I'm leaving. See ya." is the worst. Be a man, treat them like men, and say something.
