The Elder Scrolls IV: Oblivion Gets Re-rated

GameSpot is reporting that the Entertainment Software Ratings Board has re-rated Bethesda's The Elder Scrolls IV: Oblivion, changing the game from 'T' for Teen to 'M' for Mature. It doesn't sound like a big deal to me, but apparently it's causing some major chaos at retail stores nationwide:
After discovering the issues in "post-release monitoring and play-testing," the ESRB initiated a review of the game's original ratings process. The board cross-examined the tape Bethesda submitted with video taken from the final release of the game, and ultimately determined that the developer understated the detail and intensity of the blood and gore in the game. In reference to the nude skin, which is inaccessible during normal play and so couldn't have been included in the taped submission, the ESRB said publishers are required "to disclose locked-out content during the rating process if it is pertinent to a rating," and that Bethesda failed to do so.

As a result, the ESRB said a number of corrective actions are being taken regarding the matter. Bethesda will notify retailers of the rating change, provide stores and distributors with M-rating stickers for all unsold copies of the game, and preparing new packaging with the proper rating and content descriptors for future copies of the game. Bethesda will also prepare a downloadable patch to modify the game's art archive and make the topless skin inaccessible, even on a modded PC version of the game.

Was a re-rating really necessary? Does the ESRB really think this is going to deter kids under 17 from getting the game?