>>273812740
No, there is nothing stopping Oculus from uploading a game with SteamVR support on their store. It's strategy that they decided they should not, given that OpenXR is in development and that they do not want the SteamVR SDK and API to be the sole SDK and API adopted by developers. 

>>273812982
What do you mean by consequences? All I'm saying saying is that Oculus was in a position without users at first and without many people buying stuff on their store, and Steam started out in VR also without many users but any new user would be more than likely to be buying stuff on their store. Along with the way APIs developed, they have thus developed slightly different strategies and decisions in order to be as successful as they can.