If someone wants to publish on Steam, yeah, probably. But if Lepton works like Proton, the game doesn't actually need to be distributed through Steam. For Proton, you can run basically any Windows executable file through Proton, even if you downloaded the file from somewhere other than Steam. I assume the plan is for Lepton to be able run basically any APK you throw at it regardless of where the APK came from. I just doubt that Lepton will bypass the Oculus DRM.