This is just the picture, which float in my head, after knowing of tb3 news.
The top 6 USB only sockets are connected to the six USB 3.0 provisioned by the C610 chipset.
The TB block would either be lacking USB 3.0 or just use a similar discrete controller that the current Mac Pro uses and optionally flow those through the TB flavored Type C ports.
Two questions come to mind:
1. Which port has charging/power delivery capability to charge my laptop?
When will Intel announce a Xenon chip that is compatible with Alpine Ridge?