The Oculus Store validator requires that the build you submit to them does not have the SteamVR online subsystem. Steam doesn’t care whether you have the Oculus subsystem active or not.
When it comes to connecting players from both hardware platforms, I’m not sure how you’d do that yet. I haven’t used the online subsystems yet. However, I would tentatively guess that if you have a platform agnostic server and match making system, it wouldn’t matter what hardware platform players are using.