There are people in that thread saying they've run egpus off it.
USB-C is a specification and Thunderbolt is a certification. They are in process on the certification.
The processors they use support Thunderbolt and people have been using Thunderbolt accessories with it (you can see that in the forum).
https://www.youtube.com/watch?v=_C2tulk2mIE
There are people in that thread saying they've run egpus off it.