Fortunately, this fucking windows partition I only keep for VR with my shitty Oculus Rift CV1 reminds me how fucked up the alternative is. I can't fucking wait to get a Steam Frame and ditch it.
I haven’t replaced a GPU on Linux, but my experience on windows has been to always uninstall and remove the graphics driver (forcing the Microsoft generic display driver) before replacing the GPU.
Then, it was just a matter of getting the drivers installed before I’m good to go. Granted, this was under Windows 10