The article claims to prove no computer could accurately simulate quantum gravity. Suppose they are right, and as a result our simulators are forced to make quantum gravity experiments (if that were a thing) give “incorrect” answers, because the real ones are uncomputable. Would that be proof we live in a simulation? Or would it be taken as proof that quantum gravity (whether loop quantum gravity or M theory or whatever) had finally been empirically refuted?
That said, if they really wanted to give us the “correct” answer-why would they bother when we could never know that a wrong answer were wrong?-why couldn’t they just suspend the simulation, run the experiment themselves, then resume it simulating the result?