Solution

Uninstall AMDVLK, you should probably use vulkan-radeon anyway.

I think there was a wine / proton update earlier today, I've just tried to launch the game from Steam and gotten the aforementioned message. I've found out that the message is common on Nvidia and Intel Arc GPUs but not AMD. I was wondering if anyone is now experiencing the same thing and if anyone knows a fix, I was quite looking forward to sinking another day into Starfield tomorrow...