It is part of the deal with the network broadcast.
Coaches know/decide who is interviewing going into half & then the other is interviewed coming back to start 3rd.
Do you get any real revealing info? No
But it's a way to get viewers more insight into the game. If there were only post game interviews, someone would want in game content.
** This won't happen for many reasons** but wouldn't it be cool to hear coordinators headsets & in game conversations live? That would be a window into how & why plays are called, etc. Imagine watching an away game, games tied late in 4th quarter, RU has the ball 4th & long close to midfield & you hear greenlight the fake punt. Waiting for the play to unfold would be awesome.
Instead we get we need to clean up some things & execute better. Need to reduce turnovers, etc.