It means they have now better simulated the ejection of stars from the center of the galaxy (ones that came so close that when they continued in their orbit the "slingshot effect" threw them out of the galaxy). The stars would not need to get close in human terms to the BH, only close enough to achieve the required acceleration to reach the galaxy or at least the local area's escape velocity. (1. the star was simulated 2. the star did not enter the event horizon 3. the star at no point traveled faster than light) This article isn't all that significant except it says basically that we can now better simulate gravitational interactions in the galaxy.