The article is a little bit breathless about this work as though evidence of solar system instability is completely novel and unexpected, but investigation in the area using simulation isn't exactly unprecedented.
Gerry Sussman and Jack Wisdom were working on the question of solar system instability in the late 1980s and Sussman and his students built a specialized computer called the Digital Orrery at MIT. They ran some very long simulations and found strong numerical evidence that the orbit of Pluto is chaotic.
Gerry Sussman and Jack Wisdom were working on the question of solar system instability in the late 1980s and Sussman and his students built a specialized computer called the Digital Orrery at MIT. They ran some very long simulations and found strong numerical evidence that the orbit of Pluto is chaotic.
https://en.wikipedia.org/wiki/Stability_of_the_Solar_System#...
These weren't obscure results; further work was published in Science. See "Chaotic Evolution of the Solar System," in
https://www.science.org/doi/10.1126/science.257.5066.56