But does it have CR 1 rats that can chew through metal?
My guess is that they're doing it to keep up with the power creep from the new spells and classes they're creating. IMO, just one more reason to, as a GM, disallow the newer books from my campaign settings. Though I do like that they're making it easier to use the books in the game, and not just as reference material.
On an editing note, in the Safari browser the apostrophes and quotation marks are all messed up.
In the article, not the MMIV.
Though I haven't looked at the MMIV with Safari, so they might be messed up there, too.