Managing Director Pete Hines took to Twitter to explain what happened:
We have been working on the CMS that runs our sites. A bug caused platforms that don't exist to show up for some games Sorry for confusion.
Hines explained that a CMS update apparently entered 00/00/14 in a number of blank fields, prompting the error.
Traditionally, Bethesda prefers to remain tightlipped on "rumours and speculation", but the publisher was burned recently over the Fallout 4 hoax and has "changed our approach on things that appear to come from us", says Hines.
That said, it has been pointed out that Hines has not specifically ruled out the possibility of The Elder Scrolls V: Skyrim coming to Xbox One and PlayStation 4... he's just not talking about it right now. The game is currently available on Xbox 360, PlayStation 3, and Windows PC.