I'd like it see a new pro display with it's own, built-in GPU.
That's not a "pro" display - its a gaming display for consumers with laptops.
Pro customers will have their own specialist requirements for both GPU (single, dual, Nvidia/AMD, compute optimised, graphics optimised...) and display screens (UHD, true 4k, 5k, 8k, size, matt, glossy, built in colorimeter, hood, which colour gamut...) and the GPU will probably become obsolete before the screen does.
Also, last time I looked, you can only get 4 lanes worth of PCIe bandwidth down a Thunderbolt cable, whereas high-end GPUs can use 16 lanes direct from the processor. 4 lanes is probably fine for games and Photoshop, but for pro/scentific work where the GPU can be as much an extension of the CPU as a graphics device...?
If you really want an eGPU and a display, just use VESA mountings to bolt the eGPU to the back of the display.
Meanwhile, the latest Thunderbolt controllers support DisplayPort 1.4 which greatly reduces the bottlenecks when connecting displays to computers via TB3 or USB-C.
Bundling things together just reduces choice and flexibility so.... oh, wait, hold the press, that's
exactly what the present day Apple would do!