If they abandoned the Rift S anyways they could opensource drivers and the community will do it.....
of course, it won't happen, no matter how Facebook likes open source in theory...

I agree with the support of Linux makes no sense not to support that but as far as Apple goes I don't think it will happen any time soon. Apples firewalls are strict, its not a good gaming computer, and on top of it you can't really customize apple's pc i.e. graphics, ram so ultimately you asking a company to bend over backwards for another company that doesn't want to lift many security features. And isn't super customizable friendly either.