I would encourage the senate to pass a bill banning de-registration entirely, aside from falling off the rolls. 95%+ of people who deregister either come back almost immediately once their 2 weeks is up, or stay away so long that they would just fall off the rolls anyways. The practice serves no clear constituency, except random ragequitters who get mad because the game doesn't deliver a comfortable win for x person or party.
If there is a special case from time to time where someone simply MUST deregister due to extenuating life circumstances where they need to be offline and where merely being listed on the census would encourage them to be active, the solution is for the mods to mute that person.
Mutes are not intended as a substitute to stop posting, as such moderators repeatedly deny such requests to begin with.