To be fair, the Vega iGPU in the Ryzen 4000 series was a hybrid design. It had an updated media block and efficiency refinements which boosted its clocks significantly. Some of those same efficiency changes are part of RDNA 2.
That said, I would love to see the iGPU go full RDNA. It would be amazing to see laptops with integrated graphics beat the last-gen consoles definitively.