It's a cool idea - your starter Pokemon being OT, and that OT not being transferrable meaning the Pokemon has additional meaning. However, many people aren't satisfied with their original Pokemon, so it would have to be something incredible stats-wise to warrant the keeping of that starter being mandatory. On top of that, not all people like the initial starters. And, if the stats in question were applied, it would lead to a highly imbalanced PVP meta in which it was starters-only - and didn't reflect the true competitive nature of PVP/PRO.