I see what you are saying, within the bounds of the article, the Basilisk, requires that our descendants are simulating our present. But by necessity, our genetic descendants would also be members of the simulated universe. Of course, they don't have to simulate the entire universe, they only have to simulate the local part that immediately affects what we do. So long as the model we're in produces equal results to "reality" it's good enough.
All simulation hypotheses discount two other kinds of descendants, intellectual "descendants" for one. Observers of the simulation who learn or are influenced by the simulants. Just like I might run a program on an emulated Commodore 64 and be exposed to some idea I hadn't considered before.
"Escapees" - e.g. Tron: Legacy, Agent Smith from the Matrix movies, The Doctor from Star Trek Voyager. Simulated mentalities which find an external host to "upload to". In the case of Tron movie, the particle laser thing constructed a body for Quora, in the Matrix movies, Smith uploaded his consciousness into a real human and in Voyager the doctor was given a portable hologram generator to let him leave the holodeck/sick bay. Any of these could potentially produce a long of descendants.
It is being run by whatever creatures inhabit that other universe. Our actual descendants will live in this, the simulated universe.
And if they decide to run a simulation, they will simulate a less or different universe, meaning they will also not be simulating their ancestors (us).
The simulation argument relies on a loop of logic that is broken by entropy.