So when Apple showed off it’s new Apple Silicon chip it showed it running on what looked like Apple’s new 6K Pro Display XDR monitor in the 2020 WWDC Keynote.
That was what they showed Maya running on, and they claimed that they were running on the Apple Silicon Transition Kit, but there is a problem there.
The Transition Kit does not in fact support Thunderbolt, which is a licensed Intel Technology. So either they were running on different hardware from the transition kit, or they have hacked or new versions of the monitor capable of running off of USB C.
Either way Apple was fudging the truth a bit here.
Honestly they should have figured out a way to include Thunderbolt 3. They have previously bet so much on the technology, and if they drop it WILL HAVE HUGE CONSEQUENCES FOR THE PRO MARKET.
Intel is really pushing to get thunderbolt more widely adopted and has even allowed it to be used on a couple of motherboards for AMD CPUs so far (source: https://www.tomshardware.com/news/amd-motherboard-asrock-first-thunderbolt-certification-intel)
Given that they've already allowed thunderbolt to be used on boards hosting a competitor's CPU, I don't see why they wouldn't do so for Apple as well. And thunderbolt is an extension of PCI over a cable, so if they go with PCI it should be possible to get Intel's blessing to make it available on a TB3 port. That's assuming they don't just skip ahead to USB4 or they don't go super-proprietary and make a new Apple Desktop Bus (the horror!).
And apparently the XDR display can possibly be fed a signal over USB-C without thunderbolt? At least it somehow can be driven by an iPad Pro, weirdly-enough. https://twitter.com/tldtoday/status/1206642911867105280?ref_src=twsrc%5Etfw%7Ctwcamp%5Etweetembed%7Ctwterm%5E1206642911867105280&ref_url=https%3A%2F%2F9to5mac.com%2F2019%2F12%2F16%2Fipad-pro-works-with-pro-display-xdr%2F