But Valve hasn't locked out the Oculus. Plug one into a computer with Steam and it'll pop up a prompt to setup SteamVR just the same as plugging in a Vive. It even includes a link to Oculus-specific instructions: you need to set it up with the Oculus app and change a setting there to enable the Oculus device for use outside the Oculus store.
(Source: anecdotal experience from plugging a Rift into a computer that didn't have a real GPU; no idea if there are any other issues.)