It's possible of course. But Starlink satellites orbit at around 500 km and LEO ends at 2000km. It requires a significant amount of energy to push things from 500km high out of LEO. And even if debris flies out of LEO it will still come down to lower orbits and get affected by drag since it doesn't orbit in a perfect circle. If the debris hits satellites in higher orbit it will most likely be satellites that are in LEO as well and thus still be affected by orbital decay. The higher things are in LEO the longer it takes to come down, but it's still not forever.