This is a solid move.

If your FC somehow magically all vanishes for 35 days and is unable to log in and literally do a zero cost nearly zero time thing like checking a house, that's extremely strange, and is in no way common thing that deserves having major game policy bent around it.

If your entire FC are gone for 35 days, then odds are they no longer have interest in the game, and someone who does should have the opportunity to use the server space you're hoarding.

That's all.