Piping up to say that I agree this feature should definitely be implemented, but that also SE needs to make sure that this house-blacklist feature either does not work on FC Members at all or does not work if the FC Member currently has an FC room in the FC house.

I don't know if this has been fixed yet, but in the past FC leaders were able to remove housing privileges from their members and essentially hold the members hostage, because they could not leave their FC without removing furnishings and demolishing a room.