All the SpaceX satellites are in LEO, low enough that even in the absolute worst case scenario (which, FWIW, is not realistic), they will all de-orbit in a couple years.
Once we are launch 1000s of satellites we are defiantly going to have servicing satellites out there. Refueling, orbital maneuvers and so on.
Even in the worst case, decades is still not that crazy. The locations are known and can be avoid.
This is a problem, but really not any kind of gigantic issue that should stop progress.