Testing for a simulation
If they find the universe does appear to be a hologram, maybe they can figure out how to test if it is a simulation. I tend to think there's a good chance it is, not based on the argument in the paper a few years ago (the "if we ever create small simulations of reality, then the odds are good that we live in such a simulation") but simply because quantum mechanics makes a lot more sense when viewed that way.
Think about trying to simulate a universe, or part of one, and the restrictions you'll have both based on the hardware (what we observe as the "speed of light" could be to cover the latency inherent in whatever hyper-parallel computing setup runs the simulation) and software - the uncertainty principle could be lazy evaluation, wave/particle duality the result of using the same code to cover both, planck length and quantum states of energy exposing the resolution of the simulation, etc. If the universe is being simulated just for humanity (or just for you) then a lot of the stuff outside our solar system could be simulated at a far lower resolution for both space and time.
In order to really prove the universe is a simulation, you'd almost need to find an obvious bug or exploit. Maybe the reason there are no intelligent aliens about is that they've found a root exploit and the admin of the simulator caused their star to go supernova to limit the damage.