Apple, at least, is smart enough not to try to claim the technology. But I'm sure in the next few years they'll try to wall off their own garden in VR/AR.
Neal's whole idea in Snow Crash, although it wasn't explicitly stated, was that the heavy processing was happening client-side, so different clients saw different things (a vague semi-transparent blob on a cheap headset would be delicately curling smoke rings on an expensive one) and it was easily degradable based on connection speed, and the protocol was essentially open source, and infrastructure was distributed enough that there were no vertical monopolies operating in that space unlike the rest of Snow Crash where pretty much everything from the franchise restaurant to the police force protecting it were vertically organized. So any attempt to vertically create a metaverse within a particular stack or corporate ecosystem is likely bound to fail, and VR as a popular technology will track with that until someone builds a portal-to-portals. I'd put my money on a new startup if it ever were to happen, because they could at least build something platform agnostic.