It's difficult to pin down, but I've seen some strange TPEs today. There's a player with all-star potential, and the TPE indicates he's a player with announcer--starter potential. Another player is a superstar, and the TPE compares him to players of HoF-ATG caliber.
I have a theory that it's players you have a bid on. I went to check to see if it was universal and I wasn't seeing it on players i looked for afterward in the TL. But the players I have bids on are definitely showing at least mismatched potentials.