Can think of plenty:

Online meetup for Disney fans: each week in a different scan of the park

Online consultation with interior design or architect: takes place in you existing house and saves travel for someone billing $x hundred an hour.

Online highschool reunion planning meeting with people spread over the world: takes place at the highschool or potential venues

Deployed military personel meeting remotely on his anniversary with his wife: takes place where they had their first date

I thought we would have already had this with photogrammetry back in 2016 when the Vive released with a camera, but that usually involved too much cleanup and optimizing geometry and couldn't be done automatically, along with the issues with reflections. I was also really surprised Google Earth VR didn't add in multiplayer soon after launch for similar use cases.