It's not ready. You can tell the one they were using was a production sample. When they order PCBs for those they order like one or two. My guy in Taiwan posted when they ordered those and it was in September. Raja said he was somewhere sorting out Vega on Twitter which all coincided with the order AMD had made for PCBs.
They have not placed a large order yet. IMO showing Vega was just to try and keep the wolves from the door tbh. It's nowhere close to release but AMD wanted to show something to go along with Zen. Which will probably increase their share price and get them more investors.
If you just assume that AMD will release at the same time of the year for GPUs you won't see them until June and in volume until August IMO.