So, since you were able to detect our simulation because of its lack of aliens, it's reasonable to assume the next run of the simulation will include aliens, right?

Or, perhaps, the last run included aliens, but it turned out to be a very bad idea and ended in an end with no results?

Therefore, there is no successfully undetectable way to run a simulation - with or without aliens. There's no way to get a result that isn't tainted by subject awareness. So, it becomes obvious that it's not a viable tool for whatever the hell the point of simulations might be, so no one is running a simulation at all.

Probably.