There's 2 things to look at regarding internal connectors here. The first is the special PCIe riser that I think will allow the GPU to be placed at 90 degree angles in 2 axes from its typical orientation relative to the motherboard. He's listed it as PCIe 3.0x16. This isn't the newest standard, but it's what pretty much everything that is currently out uses, and you'll see very little performance difference for a while yet. I think most GPUs don't even use the full x16 and the 4.0 spec is mostly for storage drives at this point. So that riser should last you through a few more generations yet. I could be wrong here, so others can feel free to correct me.
I think your main question is the cables to move the video outs from the GPU to the back panel. It looks like these wouldn't be a hub, but are simply cables that plug into the graphics card, and route to the back of the case. They're basically extension cables. The port selection is very reasonable too, and he's using the latest standard available on all graphics cards. The only oversight, which is already pointed out, is the exclusion of USB-C/Thunderbolt. but you can work around that, and I wouldn't be surprised if Michael fixes that in a later Rev.
I think these extenders are included with the case. I'm wondering how much of a special order they are. It's going to be a while yet before you start seeing them hamper performance due to newer specs. Possibly even with an RTX3080 Ti or whatever they call the next one.
Thank you for your reply. If they're just extension cables, that makes the "this hurts upgradability" sentiment I've seen sound a little silly, since it'd be possible then to just swap them all around, even if a PCIe cable would be expensive later on. That's why I wanted to clarify. I can see the downside of no USB-C but I personally don't make use of those devices. Now I just have to hope I can click the order button fast enough.