IF Fred comes back to college coaching, he will do whatever he and his family thinks is best for them obviously.
I think everyone on here can agree that Fred has been an amazing ambassador to ISU through the years and put the program on the map as a player and back on the map as a coach. His departure stung due to the timing, but I get it - he had had a recent brush with his own mortality and saw an opportunity to grasp his career dream of coaching in the NBA.
If Fred coaches in college again, the fan nervousness to me stems from two areas. 1. If he coaches any team to a final 4/championship, the question will always be whether he would have done that here if he stayed and 'why couldn't that be us'? 2. If we lose recruits to him at a geographically close school like Nebraska, KU, etc. I am less concerned with #2, as Prohm and his assistants have shown a phenomenal ability to recruit. That isn't going to change if Hoiberg re-enters the market. We may lose a recruiting battle against him, but so what, we lose recruiting battles to Self too. Also, regarding #1, who knows - Prohm may coach us to a final 4/championship - he has certainly shown the ability to build and coach a team!
Fred will do what is best for him and his family, and he should. I am sure he does consider his legacy at ISU when making these decisions, but I'm also sure it will not dictate every decision he makes for his family's future.