It's interesting. I recently spent almost a year around a major college basketball program with access behind the scenes to almost all areas the team was in and the layout was such that the coaches weren't really in the "locker room" and shower areas. Their offices were far from the locker rooms. I don't remember them being specifically kept out of those areas, but the areas where the coaches went and addressed the team were separate from those areas. These programs have pretty massive resources, so it's different from the days of the coach's office being around the corner from the showers. The coaches not really being in the locker room a lot seems somewhat common from my exposure to these things, but I'm sure there are lots of different experiences out there. That doesn't excuse the coaches from responsibility for everything that happens in the program, but just noting what I saw.
I don't understand the application of the fox and the hen house here though. Are you saying that the member of the coaching staff would be the fox in the hen house? That doesn't compute.