Jason Snell at Macworld has an article, Forget Everything you know about the Mac Pro which is speculation on Apple Silicon.
Of course we know some, like a bigger version of the M1 Max with more cores and more graphics cores and more memory.
And of course that means a smaller box than the current Intel Mac Pro.
And of course less expansion, because it is unlikely to have PCI slots especially since it doesn’t need an afterburner since it is built into the processor now, and only thunderbolt for expansion.
So really we are not saying anything new here. And sure it is all speculation.
I personally hope for more storage options. It would be great to have at least 2 banks of raided SSD’s, as I am sure there won’t be any room for spinning hard disks (though I would love a bank of 4, but am sure that will need external needs).
Honestly the New MacPro will likely be pretty damn small, but with some fans to cool the processors down for better performance.