Multiple sources confirmed AMD showcased its Vega GPU architecture to members of the press at a secret press event in California.
Everything discussed at this event is under NDA but usually juicy stuff starts leaking in the weeks before the official launch. At the moment, we don't know what was presented about Vega and Zen.
You won't have to wait long for more details though, AMD is hosting a gamer-centric "New Horizon" livestream event on December 13. Some details about Vega are expected to be revealed at that event, with more to follow at CES 2017 in January.