When a coach takes over a new team, I think, in addition to the regular "welcome" e-mails from the assistant coach and school AD, you should receive an automatic e-mail regarding potentials (similar to the "player thoughts" one you receive after the first exhibition game each season) for players on the roster he/she is taking over.
Yes, this would make the regular Player Thoughts e-mail a tad redundant (other than the latter will include any signings the new coach makes...), but it would also assist new coaches in decision-making during their first recruiting cycle with their new team. For coaches looking to establish a certain personality to their teams, this could help sort players that will or won't develop into the desired system by their senior seasons. It would also help identify dead weight on rosters that may have been under Sim control.
Case in point -- I took over a D2 team this season that had been Sim AI. One of my players was a PF rated 470ish...not good by D2 standards, but he also hadn't seen a lot of action and had a GPA that suggested practice time may have been curtailed by study hall minutes. I was wrong -- he was simply a player that I barely would have considered for my D3 team and who has no purpose on a D2 roster. He won't hit 500 by the end of his senior year...had I received the player thoughts e-mail and seen all the "Low Potential" categories, I would have axed him on the spot. As it was, I gave benefit of the doubt and was wrong. Due to my desire to maintain class balance, I'll probably have to go the transfer route to fill that spot, or simply accept an 8-10 minute per game backup for next season who just happens to have the luxury of an A- IQ in my offense and defense.
I can't see a "down" side -- I think its within the bounds of reality that a new coach and his staff would hustle to ID the talents of their new team and would be aware of high/low potential areas like found in the Player Thoughts e-mail. Providing it upon signup simply enables coaches to possibly get a year quicker start on establishing their identity with their new team by allowing them to make more informed decisions about rescinding scholarships that first year.
My latest two-cent thought.