I can certainly agree with your analysis and prediction. I was expecting them to ditch the naming this generation. Nvidia has made indications they're not interested in making entry-level GPUs any more since they compete with iGPUs too much. Since OEMs occupy that market mainly and minimize cost religiously, it makes sense that an iGPU is much cheaper than a second GPU in almost any case.
I don't expect Nvidia to release much before Vega launches. I'd be amazed if Vega is even that much better than say Pascal +20% performance, which Nvidia should indeed be able to counter easily. I'd wish it was amazing, but I'm not expecting a $300 GTX 1080 equivalent.
I'm expecting the "RX490" to be around GTX 1070 performance for $350 with an "RX Fury" coming in at GTX 1080 performance for $450 and an "RX Fury X" above GTX 1080 performance at $600.
At that point I expect Nvidia to "unleash hell", introduce a new series within the month, all one-upping AMD once again. Atleast that's what I think will happen if Vega is just another evolution and not a revolution. Their marketing campaign seems to be hyping already known facts as some kind of secret news like Volta not coming this year (duh) and 4K @ Doom capped at 60fps being some kind of impossible mountain to climb.
tl;dr
I'd love to see Vega to be a true surprise in performance per dollar, but they've been doing the same game for a few years now, hyping and just being good but not great.
