Like caring for their farm when the other's unavailable and such?
Seems like a good idea.
Maybe the saves could be updated when the other goes on that server again.
It being an option would also help, so both/all can decide if they want it like that or not.
That must be done at creation, of course.
There's just an issue of trust, though, as some who may not be trustworthy, could use that to do bad stuff to the farm, when no one's looking.
But that's the risk of choosing such way to play multiplayer, then.
i don't know if it's possible or doable from the team's perspective, but it'd be nice for some who'd lose their host for a while or forever(people could stop playing it suddenly).
This is just my thoughts, i don't play multiplayer, so i just thought about how it'd look like, and what good reasons there are to have such option.