Technically yes, as long as it will de-orbit in less than 25 years you don't need to. That being said not being able to de-orbit on command or maneuver out of a collision course is going to make getting tens of thousands of such satellites approved much less likely.

Also they are used as part of the normal operation of the satellites anyways, ~60 are launched together in one big clump and then the ion thrusters get them into the individual target orbits and keep them there over time (until fuel runs out trying to keep the orbit on track or the satellite stops being operationally useful), so getting rid of it does make it lighter but not necessarily better suited.