Okay lets take this to a logical conclusion!
TESLA most likely did this for two obvious reasons
1) Supply Chain
2) Reducing the BOM, any AMD processor is much cheaper than a Intel processor
Now it might be that Ryzen for its cost and performance might be better choice for TESLA
On the technical side, most of the rendering that's going on the APPs on a TESLA are pretty reasonable for a RYZEN or a INTEL
Once might argue that once Tesla FSD evolves to newer features on image processing, then a better processor would make sense. Even this is also tad bit far from logic, Don't want to go deeper into image processing and CNN that FSD uses thus far..
This process choice is just BOM and Supply Chain.
Duh i am on this forum to much! i just want my TESLA to be delivered quickly