Most civilizations - unless they are in some very confused stage of learning about their equivalent of quantum mechanics - will know better than to utter anything this confused: you cannot see things that are not real. Even when you hallucinate you are seeing a real hallucination, there is something actually happening inside your brain that makes you see it.
To see something is to be affected by it; and real effects cannot be produced by unreal causes. If the world-history of a photon going down a particular pathway affects your experimental results, then that world-history must have happened as much as anything ever happens; if all possible combinations of qubits contribute to a quantum computer's actual output, then all possible combinations of qubits must have been 'real'. Only real causes have real effects; so whatever affects a real thing must also be real. Causes and effects don't have be equally real - you can set things up so that a more real observer can see the output of a less real process - but the cause must be at least a little real.
(Though these margins are, again, too small to contain that logic whereby 'realness' for the purpose of 'the conscious entities described inside a causal system can find themselves there' and 'realness' for the purpose of 'real effects have real causes' are necessarily the same kind of 'realness'. Without that connective step, the above is just a bare appeal to philosophical intuition - but a philosophical intuition that happens to be correct.)