In a number of tweets AMD employees have confirmed that they are launching Radeon RX Vega in one month at SIGGRAPH. This was already mentioned at the Computex press-event.
But with everything Vega, you just don't know for sure right. Interesting that the answer is plural "our new Vega products", e.g. in multiple Vega Products. Obviously an Air and Liquid cooled version is expected. These tweets have been shared bu AMD staff, I'll just leave it at that:
Radeon RX Vega Confirmed launching at SIGGRAPH
