I would guess this might be Kirk Ferentz's last season. I have to wonder how the conversation between Barta, Kirk and Brian went at their annual review after last season. Don't you think there had to be a discussion concerning how many more seasons Kirk planned on coaching, while Barta is considering whether Brian will continue as o-coordinator?
The Ferentzes must have thought that when they got the transfer portal players on the offense like Kaleb Brown (a 4* recruit from tOSU who is an Iowa second team WR), Erick All, Cade McNamara, and the two offensive linemen (who are not starting because apparently the existing o-linemen are better than the transfer portal o-linemen) that Brian's reputation as a coach would be redeemed. They thought they were going to show that the offensive performance the past two seasons was a player talent problem, not a coaching problem. Brian could then find another job in football at a high level after this season's redemption.
Brian's coaching acumen is what it has been demonstrated to be throughout his tenure. Brian's offenses have underperformed his predecessor Greg Davis's offenses, and Greg Davis's 5 offenses were well below average.