Just going to ramble/speculate on AMD's plan here.
So I'm going to assume that top spec gaming Vega with all drivers running properly is going to compete with an overclocked 1080/1080ti. Lets assume that Poor Volta was an actual jab at volta (I have a hard time believing that they would do this intentionally).
One thing that adored mentioned once was "that there is no such thing as a bad GPU just a bad price". What if vega is actually competing with the 2070? I thought about this and in adored last video, an AMD exec mentioned in some event that they were going to offer significant performance gains for the given price point, similar to what Ryzen did. Aiming at the 2070 market segment would make this statement true.
Looking at Nvidia record. The 970 came out and offered 780 performance for the mid range market. The 1070 came out and offered 980ti performance for the mid range market. We can assume that the 2070 will come out and offer 1080/1080ti performance for the mid range.
But what if AMD beats them to it. What if AMD plan is to come in and offer 1080/1080ti performance at 1070 (or less) price; exactly what Nvidia would want to do with 2070. Where would that leave the 2070 when it launches in ~6 months time?
For people with 1080 and 1080ti this will be a disappointment (but then again you are a minority

), but for everyone else that's going to be great. For people running 290x and furys; to those running 970 and 980 (maybe even 1070); that would be a significant performance boost for them. Personally I'm still running my 970 that i got on release; I don't plan on upgrading this year but if something came out at a really good price my plans could change. IMO I think the people in that price bracket are significantly more than x80 and x80ti gaming markets (probably more than both combined) and AMD is aiming for them.
Now many people will say that Nvidia could lower the price of the pascal range (potentially start a price war with AMD); which I agree with that will help shift the last few units of pascal cards. I don't think they will though because firstly it doesn't solve the 2070 problem; which is that Vega has already attacked its market segment. Secondly it would make the 2070 launch more awkward if 2070 came out around the same price as the discounted 1080/ti while offering the same performance. The last thing Nvidia wants to do is start a price war that spreads to the Volta launch because Nvidia couldn't/wouldn't undercut them because they can't afford to; they need to recoup their R&D budget which is orders of magnitudes bigger than AMDs.
The big question is could AMD release a HBM2 card that cheap. If the main target for vega cards is the server market (I can see them offering bundled discounts with epyc systems) and if there plan is to recoup most of the R&D costs from the server business then maybe, they could.
TLDR: RX Vega is going to offer 1080/ti performance at 1070 prices to compete with the 2070 and take as much sales from it as possible before it launches because at that price segment the market is bigger.
What do you think plausible business plan, or would it not work?