Imo your topic is more "what define clearly a simulation?"
If a simulation is just reproducing real world rules then clearly it is not.
If simulation is reproducing created world rules then it is.
That's where elite is to me , between these to , it's like a fantasy book : taking element from our world , and adapting/adding some others . So it is a simulation in his own world but not from our's.
Elite world have some rule and consistency among it but it is not as complicated as our world.
Problem is, if you consider that simulation can be simulation from crafted world rules , well, many games become simulation.
So my real feeling about what a simulation is : the level of complexity (to reach our complex world rules). If a game have complexes rules where not everything is automated , it slowly become a simulation.
Elite simulation greatest part is , space interaction , and flying ships , with newtonian model. (well except ramming)
But how the world works , mission , guns , NPC , even engineers , are not a simulation, even supercruise is out of it.
In conclusion to me elite is a simulation when it comes to flying ships and how they handle in space (not perfect , but complex enough). And they put this simulation in a created universe that have his own rules.
And tbh that make a great game.