I also have recently moved to Ryzen 9 3900x.
And the game freezes on the "loading" text.
But you can actually fix the game still.
PC Gaming Wiki to the rescue: https://www.pcgamingwiki.com/wiki/The_Technomancer
Here's the bit:
"Issues fixed •
Infinite loading screen upon the game start up •
On a system with more than 4 cores enabled user needs to disable the extra cores
Open start menu
Type 'msconfig' and start the System Configuration tool that shows in the search
Click on the 'Boot' tab
Click on the 'Advanced Options' button on the middle left of the window, a new window should popup
Tick the 'Number of processors:' option at the top left of the window
From the dropdown list choose 4 as the maximum enabled cores
Press 'OK' and then 'Apply'
You will be presented with a possibility of rebooting the system. Reboot the system.
After reboot verify you have only 4 cores enabled"
I tried it and it works. Just need to remember to activate the rest of the cores when finished with playing.
Not a perfect solution for sure, and come on devs get a grip... But at least it makes the game work.