The company disclosed today that it has discovered a breach of more than one billion user accounts that occurred in August 2013.
You may well be right, they have considerably changed the content of their original story now.I think it is actually the 2013 hack that the story was sourced from. The BBC seem to have interpreted that there has been another hack?:
https://techcrunch.com/2016/12/14/yahoo-discloses-hack-of-1-billion-accounts/
My highlight.