The original Hyperloop proposal was elevated, so ... yes.
As far as I am aware of, there are three different things: 1) Hyperloop as originally planned, for above-ground long-distance travel 2) tunnels under dense cities, for existing cars carried on, perhaps, electric sledges, 3) a "verbal agreement" mentioned by Musk about an Easy Coast tunnel hyperloop which no government official has confirmed, and with no concrete plans that anyone can say anything about. Will it be bored? Will it be 20+m down? What route will it take?
So, what is it that you expect will be bored? A, ~5 meter wide high-speed tunnel from L.A. to San Francisco across multiple active faults? (Or rather, two such tunnels as you want traffic in both directions.)
Gas pipelines are only, what, 100-150 cm across? They are built to either move with the ground or force the earth move around them. Any such movement is going to have rather less than a 100km radius. How do we scale up that knowledge to a Hyperloop tunnel? Will we also built the Hyperloop tunnel out of steel?
This isn't bike shedding. We know it's possible to build a Hyperloop by throwing enough money at the problem. For example, we can solve above-ground thermal issues by simply enclosing the hyperloop in a flexible insulated chamber and running heaters or chillers to keep the temperature inside constant. But that would be prohibitively expensive.
Since there isn't a concrete proposal for what some high-speed long-distance tunnel is supposed to be, there's nothing to bike shed. Tom Swiftian dreams of the World of Tomorrow must first demonstrate they can overcome the hard realities the the World of Yesterday discovered.
Why didn't Tom Swift dream of upgraded sewage treatment systems?