Look at the URL. The datestamp is set to the 5th instead of the 8th, when the embargo for the news lifts. The only reason this post was published early was because a stupid typo when scheduling it.
Yeah, I know. For some reason, when you put a past date in Wordpress and press "schedule," it publishes the article automatically. That's all this was -- a typo.
I'm the author of this post. The article has been updated to clarify that I accidentally published it one day before the embargo lifted. GitHub will formally announce the news tomorrow.