HP recently switched from Kaby Lake G to i7-8750H and 1050 Ti Max-Q on the Spectre x360 15 if that gives you an idea. Ice Lake would be great for performance and battery life, except that for some reason OEMs aren't willing to invest in U-CPU + dGPU systems.
I hope the 9575 successor will go full AMD, for both the CPU and dGPU. Intel should also release its hold on TB3 controllers by then too and we can finally expect some price drops.
That is if Dell improves the soldered RAM, small battery, poor keyobard, I/O and speakers. Being first gen, the entire hardware was a giant mess and on top of it, overpriced by a huge margin compared to the Spectre x360 and Yoga 730 15.
An ideal performance 2-in-1 would be a Thinkpad X1 Extreme Yoga with the whole retracting, spill-proof keyboard (X1 Yoga) and the front-facing soundbar hinge (Yoga C930) should Lenovo decide to make it. Now wouldn't that be amazing?