Sounds very similar to other sets with "special" cards in the set, like the EX sets that had the foil Basic Energy cards, where the ratio seemed to be 1:3, or with EX: Unseen Forces and the Unown (ratio seemingly 1:3). You probably also pull fewer reverse-holo rares in Platinum: Arceus for that matter, because when there are foil Basic Energy or special subsets of Pokemon, the "special" cards are always "rares," and most boxes seem to have close to a 12-12-12 ratio of reverses of commons, uncommons, and rares, respectively.
At least that's my hunch.