I'm not suggesting such themes as a cave or a space station, that is the wrong starting point for design. You start with what you are trying to tell people or have them do and then what you minimally need to accomplish that, and for VR where you locate that in space. You will have to come up with a design sauce that things will be themed in, sure.
A office is just a bunch of rooms stacked on top of each other, I would object to that if it was set in a cave or a space station too. That very literally stacking on top of each other is a necessity for RL offices that is not really the case for a Virtual locations. Specifically when you see the amount of space in front of it that seems to be without function, other than framing a rectangular building.