Historically they announced very low volume chips(high end usually) before ramping volume.
Correct, but as you saw with the Lenovo leak there's only going to be a tiny amount of Icelake out there. Broadwell's ramp was way higher than this.
Aurora's target performance must be at least 5 times more powerful than Summit, which uses 14nm Power 9 and 12nm V100, it won't be achievable in 14nm unless they make it ridiculously bigger.
That's why I was suggesting that the GPU has to be on a non-Intel node. The GPU can't be on 14 nm.