IIRC, fuel on satellites is used gradually over time to maintain a controlled orbit and orientation, not to actually provide altitude to keep the satellite up, or for dramatic changes in orbital parameters.
That's generally true for higher orbits. In lower orbits there's still a tiny bit of atmospheric drag so satellites have to periodically boost themselves. And in the special case of spy satellites they occasionally do make dramatic changes in orbital parameters in order to observe a particular high-priority target at a particular time.