I like to think different. VR could change Pro workflow.
I think you're missing a fundamental problem - macOS, because of Apple's reliance on AMD hardware, does not have access to the graphics hardware necessary to generate the VR workspaces where Pro app work will be done.
Imagine if the Mac still had a 512 pixel black & white display - how would Final Cut Pro, or Divinci Resolve even be imagined as a thing that could be done on the mac?
A VR workspace, is basically running two of the highest detail, most hardware intensive first person shooters at once.
That relentless progress of higher and higher quality isn't going to plateau until simulation is indistinguishable from reality, and until the plateau, you don't have an in with secondrate hardware.
Noone is going to buy a mac to use VR Pro apps, if they can't get a decent workspace. Noone is going to write VR-based pro apps for macOS, if there isn't an install base of hardware capable of generating the workspaces. THATS why Steam is relevant - noone is investing in making mac VR apps, because there literally aren't enough potential customers to recoup the investment, and those customers there are, will only be getting secondrate experiences.
Apple coming up with their own non-steam based VR platform isn't going to solve that, just like Metal didn't solve AMD being less-capable than Nvidia at powering 3D engines at high resolution.
VR for doing work makes high-quality-graphics gaming look like a picnic.
Forget Steam, it's not Apple's business. Apple will follow their own paths. At WWDC they could introduce the first generation of a VR user interface (based on the invitation logo). It'd be quite usable even on a 2D screen. Apple VR hardware will come later, when the software is ready.
By VR user interface, are you talking about just Finder in VR? Because, aside from a VR based file manager, there literally isn't anything for Apple to contribute here. That's the thing - a VR computer isn't just a desktop computing environment with goggles thrown in, the very idea of there being an operating system that you interact with, doesn't have an equivalent in VR - A mac running Gravity Sketch, is exactly the same as a windows machine running Gravity Sketch. From inside, there's no way to tell what system you're running on - the operating system itself is a commoditised, and redundant factor. You're no more going to care about, or interact with macOS than you did about, or with, Open Firmware in the PowerPC days.
Literally, all that a VR system needs furnished by the operating system, in terms of user interface, is a way to launch the "home" app. On windows, you have Steam Home, and Viveport for HTC headsets. So, you press power on the computer, the operating system boots, auto-launches the home app (which headset and appstore makers aren't going to give up making), and you put on the headset and go. You don't actually use Windows at any time.
But there's no "path" for Apple to lay out in this. VR is not just a desktop operating system in 3d, the very concept of standardised UI elements and behaviours, so central to Apple's entire history, simply has no equivalent in VR. Every app is a self contained universe. There's no standard controls, no standard UI elements, nothing of Apple's DNA in creating unified, standardised experiences is applicable to VR as a computing platform.
If you think there's something Apple can contribute here, I'm all ears, because I'm using this stuff to do work, and I can't see it. I've messed around in Gravity Sketch, and logged a fair bit of time now in Tiltbrush. The desktop operating system as we know it, simply has no applicability to a VR station.
My bet is that Apple VR/AR is meant for a daily computing duties and for a new kind of entertainment, and the real GPU power will be delivered from inside "the goggles". With Apple GPU.
That's a lot of handwaving and wishful thinking - it takes an Nvidia 1080ti to make a usable VR environment today. That's not because of inefficiency, that's just how much raw power is needed to do the work, and that is not anywhere near "enough" that someone would say "I wouldn't care to have more if it was available".
Paring them with an iToy, AppleTV and/or a Mac will create a new kind of tool. Mac will create the 3D user interface, that is attached to the AR world within the goggles. With low latency, ProMotion, FaceID tech expanded to a greater scale and highly sophisticated sensors it will be totally different experience than anything before.
None of these things you're talking about are answers to the problem of: How will Apple be able to drive a VR workspace, and get developers to write apps for it, when their hardware isn't capable of doing the job as well as Nvidia solutions.
Making OS's ready takes time. I believe that Metal was the first step. Now Apple is ready for next_step.
Metal is not going to make AMD or Apple GPU hardware outperform Nvidia hardware at generating VR workspaces.
Again, that's what this all comes back to - it's like saying Apple is going to make a great new platform for digital painting, with only greyscale displays.
Look at the way all the blogarati in the mac world gush over Retina, that they couldn't imagine anything more detestable than being forced to go back to non-retina displays - that level of advancement, every year or two, is where VR is going for the next decade. Do you think the people Apple wants to be Apple customers, are the sort of people who'll settle for secondrate viewports onto their VR workspaces, when the operating system is invisible?
