My guess as to what will concretely emerge is protocols/standards for things like 3D user avatars and world hopping, so that worlds hosted by anyone can be linked up, rather than only uploaded to a proprietary game with rules/technical limitations decided by the game's devs. The "Metaverse" would be to 3D environments what the Web is to HTML pages.

But the article's "Ask 50 people what the metaverse means, right now, and you’ll get 50 different answers" is very true. I have no idea if this is what Facebook or Epic Games have in mind.