Luckily I have already made mistakes before and I had a full drive backup with Carbon Copy cloner, so I was able to roll it back. However, I was not expecting this particular issue, and I haven't seen any information about it yet..
Post upgrade my system would auto reboot before getting to the display drivers (roughly, I didn't have verbose logging on at the time). I don't see any updates in the AMD vanilla git, so I am assuming this is either really new, or I have some garbage in my EFI that has caught up to me.
For now, I am just curious if anyone else has had an issue with this update.
CPU: Ryzen 7 2700x
GPU: Sapphire RX 570 8 Gb
MOBO: ASRock B450 Pro4 (bios p3.60)
RAM: 32 Gb DDR4 Corsair Vengeance LPX
SSD: WD Blue 3D Nano SATA M.2 500 Gb
Mac OS X 1.14.6 Mojave (18G4032)