Honestly I'm not sold, this has been tried a dozen times and sometimes with a hardware user bases larger than fakebooks current Rift base. Remember Playstation Home, had a user base of what, 40 million people, dead. Second life, dead. Those weren't VR, but is an even steeper barrier to entry. Plus VR chat currently exists for the actual innovators/first adopters of this tech (which is critical for something to grow) and that even though its available on Index/Vive/Rift and windows mixed reality has a tiny user base.
I guess time will tell but right now, this is in the fad column for me. To be clear, i am sure VR gaming will continue to grow as the technology becomes more accessible, but I don't believe social VR will catch on and become mainstream.