I think it depends on how well ASUS can create a standard here. What speaks in favour is that the graphics card can be used without performance losses. What speaks against it is that not every manufacturer now goes and builds in a power supply (with power passthrough) and extra connections. A PCIExpress 8-lane would be quite sufficient for just one eGPU. That would only be the longer right-hand part of the connection without USB-C.
However, I also think that if the concept is successful, which I assume it will be, ASUS will surely release several variants (laptop, eGPU combo).