When Harbaugh made the decision to get rid of Alex Smith he showed his true colors. He went from a guy that everyone liked, who finally had his chance, then moved him off the team for kaepernick. It was at-best a short-term solution. But the team obviously saw how loyal Harbaugh was and saw he will do anything to get a win NOW, even if it costs the team many wins in the future.
Based on how Harbaugh "did" Alex Smith, I'm betting Urban is pissed and want a chance to rub his nose in the dirt about it.
The Timing os this hire is superb too: We will go to Ann Arbor with one of our best team next year. I am very confident in our team. Then, the following year its in the shoe. Harbaugh may realistically be 0-2 to start the series should he take the job. And harbaugh has very little patience, so the players up there will be walking on egg shells. And of course, He would bail eventually with the constant second-guessing of his decision.
Bottom line: This is fun to watch. They can have Harbaugh. He is, and never will be a good long-term coach. Win-now he is good, but he motivates guys to lose as much as win. I'd lose on purpose just to see him throw a fit.