I'm thinking that chances of Facebook turning into a 'metaverse' are less than the chances that Facebook will turn into the next MySpace. But perhaps I'm overly cynical.
It was pretty clear to me that had Blizzard a bit more vision they might have been able to pull this trick off with World of Warcraft but at this point I think that too is off the table.
One of the more interesting things I've learned over the course of my career is that the ability of an organization to "change" is tightly governed by the ability of its leadership to "see". Truly the most fascinating part of my time at IBM after it had acquired Blekko was seeing a company from the inside that actively at war with itself between the folks who wanted to modernize it and the "old guard" who wanted to keep the status quo.
As an executive it is important to understand that in order for change to happen, all of your leadership has to see their own role in the new vision and how they will be successful, otherwise they will treat it as a threat and work against it, both actively and passively.
Given how Zuckerberg has handled the disinformation problems at Facebook (essentially by throwing other executives under the bus rather than take ownership) it seems unlikely they would be able to pull of such a transformation. Mostly because the other executives would be sabotaging efforts for fear they would be thrown out.