Wednesday, July 18th
Reviews Of The Blackmagic eGPU
This confirms what I feared: the GPU is not replaceable. However, the enclosure and the price still seems reasonable considering all this. Sadly, it might also be the best Thunderbolt 3 hub available on the market (pricey, but at least it comes with a free Radeon Pro 580).
Update 7-19-2018: Macrumors Reviews The Blackmagic eGPU