To emphasize, the ODO focuses on contemporary English and is updated more quickly, while it generally takes longer for words to make it into the OED. Prescriptivists can rest easy, for now: We probably won't be seeing twerk or selfie or squee in the pages of the OED anytime soon.
So why are we seeing so many false reports? Oxford University Press' clarification, while bolded, does come near the bottom of their press release, so perhaps some journalists just looked at it and went "TL;DR."
And I can't help but wonder whether some portion of these writers avoided the distinction deliberately, to boost their article's outrage factor and, in turn, their page views. Many articles report that the terms have been "Added to Oxford Dictionary," which is correct, but a bit misleading. Even the New York Times went with the headline "Oxford Dictionary Learns How to 'Twerk,' " and simply notes, within the article, that "Oxford Dictionaries is responsible for reference works including the Oxford English Dictionary," without ever saying that the dictionary in question is a different one entirely. (And this is far from the first time this has happened.)
Credit goes to the Associated Press, ABC News, Forbes, Time, Quartz, and the other outlets who got it right. Their articles might be less buzzworthy, but at least they're not deliberately confusing peopleand making us all dumberjust to boost page views. That's the kind of thing that really makes me want to vom.