Looks like you where right about the udev rules earlier, I ran a pacman command to find all untracked files in /usr and I found /usr/lib/udev/rules.d/50-remove-nvidia.rules was there. Contents:

# Automatically generated by EnvyControl

# Remove NVIDIA USB xHCI Host Controller devices, if present
ACTION=="add", SUBSYSTEM=="pci", ATTR{vendor}=="0x10de", ATTR{class}=="0x0c0330", ATTR{power/control}="auto", ATTR{remove}="1"

# Remove NVIDIA USB Type-C UCSI devices, if present
ACTION=="add", SUBSYSTEM=="pci", ATTR{vendor}=="0x10de", ATTR{class}=="0x0c8000", ATTR{power/control}="auto", ATTR{remove}="1"

# Remove NVIDIA Audio devices, if present
ACTION=="add", SUBSYSTEM=="pci", ATTR{vendor}=="0x10de", ATTR{class}=="0x040300", ATTR{power/control}="auto", ATTR{remove}="1"

# Remove NVIDIA VGA/3D controller devices
ACTION=="add", SUBSYSTEM=="pci", ATTR{vendor}=="0x10de", ATTR{class}=="0x03[0-9]*", ATTR{power/control}="auto", ATTR{remove}="1"

looks like EnvyControl left some extra files after uninstalling.
Personally, I think it’s pretty weird that it put runtime files in /usr/lib, if they where in /etc I would have found them quickly.
The GPU is back on the bus now and I can run optimus-manager to get my extra screen. Thank you for the help troubleshooting this issue.

[ 1501.764754] nvidia-nvlink: Nvlink Core is being initialized, major device number 234
[ 1501.764761] NVRM: No NVIDIA GPU found.
[ 1501.765791] nvidia-nvlink: Unregistered Nvlink Core, major device number 234