So there you go, straight from the horse's mouth. As I suspected, it's not a bug in the game at all. As it turns out, it's not even an error on my part (which I was pretty sure it was). It's simply that the way OOTP 9 displays scouts' ratings has fundamentally changed. Take special note of the point about favoring tools vs. ability and the impact that has on over/underestimating talent. I know my scout favors ability, so I'm going to have to keep in mind that ratings I see may be somewhat lower than reality.In OOTP 8 almost all prospects were overrated by the scouts, we have changed that in OOTP 9... in fact, the whole scouting engine has been rewritten, so you cannot really compare the two anymore. In OOTP 9, when the scout favors tools, then he's more likely to overvalue the player... and if he favors ability he'll more likely underestimate the talent.
The main function of this change in ratings is twofold. One, it will make reading the text scouting reports generated for each player important. Those reports will give you a better feel for what your Scouting Director believes a player is capable of. Two, it will place a greater level of importance on statistical analysis of a player's performance. Owners who can use a player's history of performance to generate a reasonably accurate projection of future growth will be at an advantage.