yeah, I think that simulation is the closest word that we have right now for describing it, like many other times a word tend to be overused to describe multiples related things, till a new word is invented
Projection? Seems most appropriate for what seems to be essentially an argument for a reified Plato's Cave.
'Simulation' has already been invented, and it pretty much exclusively refers to things that are not fundamental to how the universe works. So it would seem like the opposite of the closest word we have for describing how the universe fundamentally works.